Stop Comparing Monthly Costs. Start Comparing Total Ownership.
Every SaaS vendor wants you to think in monthly increments. $65/user/month sounds reasonable. $95/seat/month seems manageable. $588/month for workflow automation feels like a rounding error.
But software decisions aren't monthly decisions. You're committing to a 3-5 year relationship with a vendor, and the total cost of that relationship looks nothing like the number on the pricing page. SaaS prices increase 8-12% annually. Your headcount grows. You upgrade tiers. You add integrations. You train new employees.
We built three detailed 5-year financial models comparing SaaS subscriptions against custom-built replacements. The results will make your CFO uncomfortable — because they show exactly how much money is being left on the table.
Key Takeaways
The Model: What We're Measuring
Total Cost of Ownership includes everything. Not just the subscription or build price, but:
For SaaS:
For Custom:
Let's look at the numbers.
Scenario 1: CRM for 100 Users
SaaS baseline: Salesforce Professional at $65/user/month for 100 seats.
SaaS 5-Year Cost Breakdown
| Year | Seats | Price/Seat/Mo | Annual Cost | Cumulative |
|---|---|---|---|---|
| 1 | 100 | $65 | $78,000 | $78,000 |
| 2 | 110 | $72 | $94,560 | $172,560 |
| 3 | 121 | $79 | $114,708 | $287,268 |
| 4 | 133 | $87 | $138,852 | $426,120 |
| 5 | 146 | $96 | $168,192 | $594,312 |
Wait — that's even higher than the conservative estimate. Let's be more conservative and assume only 5% headcount growth and 8% price increases:
| Year | Seats | Price/Seat/Mo | Annual Cost | Cumulative |
|---|---|---|---|---|
| 1 | 100 | $65 | $78,000 | $78,000 |
| 2 | 105 | $70 | $88,200 | $166,200 |
| 3 | 110 | $76 | $100,320 | $266,520 |
| 4 | 116 | $82 | $114,144 | $380,664 |
| 5 | 122 | $88 | $128,832 | $509,496 |
Even with conservative assumptions: $509K over five years. And this doesn't include the Salesforce add-ons most teams end up buying (CPQ, Marketing Cloud, additional storage), integration costs, or the Salesforce admin you'll eventually need to hire.
The realistic total with add-ons, integrations, and admin overhead: $550K-$650K over five years.
Custom Build 5-Year Cost Breakdown
A Core-tier CRM replacement built for your specific workflows:
| Year | Cost Component | Amount | Cumulative |
|---|---|---|---|
| 1 | Build ($40K) + Maintenance ($8K) + Hosting ($2.4K) | $50,400 | $50,400 |
| 2 | Maintenance ($8K) + Hosting ($2.4K) | $10,400 | $60,800 |
| 3 | Maintenance ($8K) + Hosting ($2.4K) + Feature Add ($5K) | $15,400 | $76,200 |
| 4 | Maintenance ($8K) + Hosting ($2.4K) | $10,400 | $86,600 |
| 5 | Maintenance ($8K) + Hosting ($2.4K) + Feature Add ($5K) | $15,400 | $102,000 |
Custom 5-year total: $102,000
No per-seat fees. 200 users costs the same as 100. New hires don't increase your software bill. And the $5K feature additions in years 3 and 5 are optional — they represent improvements your team actually requests, not features a vendor pushes on you.
CRM Verdict
| SaaS (5yr) | Custom (5yr) | Savings | |
|---|---|---|---|
| Conservative estimate | $509,496 | $102,000 | $407,496 (80%) |
| Realistic with add-ons | $600,000+ | $102,000 | $498,000+ (83%) |
Scenario 2: BI Dashboard for 50 Users
SaaS baseline: Tableau Creator at $75/user/month for 10 creators + Tableau Viewer at $15/user/month for 40 viewers.
SaaS 5-Year Cost Breakdown
| Year | Creators | Creator $/mo | Viewers | Viewer $/mo | Annual Cost | Cumulative |
|---|---|---|---|---|---|---|
| 1 | 10 | $75 | 40 | $15 | $16,200 | $16,200 |
| 2 | 12 | $82 | 48 | $16 | $21,216 | $37,416 |
| 3 | 14 | $90 | 56 | $18 | $27,216 | $64,632 |
| 4 | 16 | $99 | 65 | $20 | $34,800 | $99,432 |
| 5 | 18 | $109 | 75 | $22 | $43,272 | $142,704 |
But Tableau is just the dashboard. Add the data infrastructure:
| Additional Cost | Annual | 5-Year Total |
|---|---|---|
| Tableau Server / Cloud hosting | $12,000 | $60,000 |
| ETL tool (Fivetran, Stitch) | $6,000 | $30,000 |
| Data warehouse (Snowflake, BigQuery) | $8,000 | $40,000 |
| Dashboard maintenance (internal) | $15,000 | $75,000 |
Total Tableau stack over 5 years: $142,704 + $205,000 = $347,704
Most companies don't realize their "BI dashboard" actually costs them the Tableau license plus data pipeline tooling plus a data warehouse plus internal maintenance time. When you add it all up, it's a $70K/year commitment.
Custom Build 5-Year Cost Breakdown
A custom BI dashboard with embedded analytics, built on your existing database:
| Year | Cost Component | Amount | Cumulative |
|---|---|---|---|
| 1 | Build ($15K) + Maintenance ($3K) + Hosting ($1.2K) | $19,200 | $19,200 |
| 2 | Maintenance ($3K) + Hosting ($1.2K) | $4,200 | $23,400 |
| 3 | Maintenance ($3K) + Hosting ($1.2K) + Feature Add ($3K) | $7,200 | $30,600 |
| 4 | Maintenance ($3K) + Hosting ($1.2K) | $4,200 | $34,800 |
| 5 | Maintenance ($3K) + Hosting ($1.2K) | $4,200 | $39,000 |
Custom 5-year total: $39,000
The custom dashboard queries your production database directly (with proper read replicas and caching). No ETL tool. No separate data warehouse. No Tableau licensing. You get exactly the reports your team needs, updated in real time, accessible to everyone without per-seat charges.
BI Dashboard Verdict
| SaaS Stack (5yr) | Custom (5yr) | Savings | |
|---|---|---|---|
| Dashboard only | $142,704 | $39,000 | $103,704 (73%) |
| Full BI stack | $347,704 | $39,000 | $308,704 (89%) |
Scenario 3: Workflow Automation
SaaS baseline: Zapier Team plan at $588/month (starting), with usage scaling 15% per year as you automate more processes.
SaaS 5-Year Cost Breakdown
| Year | Monthly Cost | Annual Cost | Cumulative |
|---|---|---|---|
| 1 | $588 | $7,056 | $7,056 |
| 2 | $676 | $8,114 | $15,170 |
| 3 | $778 | $9,331 | $24,501 |
| 4 | $894 | $10,731 | $35,232 |
| 5 | $1,028 | $12,340 | $47,572 |
But that's just Zapier. Most companies also use Make (formerly Integromat) for workflows Zapier can't handle, plus n8n or Tray.io for more complex orchestration. The realistic automation stack:
| Tool | Year 1 Annual | 5-Year Total (with growth) |
|---|---|---|
| Zapier | $7,056 | $47,572 |
| Make (supplementary) | $3,600 | $24,300 |
| Integration maintenance (internal) | $10,000 | $50,000 |
| Failed automation debugging | $5,000 | $25,000 |
Total automation stack over 5 years: $146,872
The hidden cost most companies miss: debugging time. When a Zapier zap fails silently, someone has to notice, diagnose, and fix it. When data syncs break between systems, someone has to reconcile. These costs are invisible on the P&L but very real in terms of hours burned and data quality degraded.
Custom Build 5-Year Cost Breakdown
A custom workflow automation platform tailored to your specific processes:
| Year | Cost Component | Amount | Cumulative |
|---|---|---|---|
| 1 | Build ($12K) + Maintenance ($2K) + Hosting ($1.2K) | $15,200 | $15,200 |
| 2 | Maintenance ($2K) + Hosting ($1.2K) | $3,200 | $18,400 |
| 3 | Maintenance ($2K) + Hosting ($1.2K) + New Workflow ($3K) | $6,200 | $24,600 |
| 4 | Maintenance ($2K) + Hosting ($1.2K) | $3,200 | $27,800 |
| 5 | Maintenance ($2K) + Hosting ($1.2K) + New Workflow ($3K) | $6,200 | $34,000 |
Custom 5-year total: $34,000
Custom workflows don't fail silently. They have monitoring, error handling, retry logic, and alerting built in from day one. When something goes wrong, you know immediately and the system handles it automatically. No more Monday-morning data reconciliation sessions.
Workflow Automation Verdict
| SaaS Stack (5yr) | Custom (5yr) | Savings | |
|---|---|---|---|
| Zapier only | $47,572 | $34,000 | $13,572 (29%) |
| Full automation stack | $146,872 | $34,000 | $112,872 (77%) |
The Combined Picture
Across all three scenarios, here's what a company replacing these three SaaS categories saves:
| Category | SaaS 5-Year Cost | Custom 5-Year Cost | 5-Year Savings |
|---|---|---|---|
| CRM (100 users) | $600,000 | $102,000 | $498,000 |
| BI Dashboard (50 users) | $347,704 | $39,000 | $308,704 |
| Workflow Automation | $146,872 | $34,000 | $112,872 |
| Total | $1,094,576 | $175,000 | $919,576 |
$919,576 in savings over five years. That's $183,915 per year returned to the business. And this is for replacing just three tools.
The average mid-size company (100-500 employees) has 15 duplicative apps and wastes $915,000 per year on unused software. Three targeted replacements won't solve all of that, but they'll address the highest-cost subscriptions and demonstrate the model for broader rollout.
What About the Risks?
Fair question. Custom software carries risks that SaaS doesn't:
Vendor dependency on the build agency. Mitigated by: owning all source code, using standard frameworks, and ensuring any competent developer can maintain it. You should never be locked into the agency that built it.
Maintenance burden. Mitigated by: budgeting $500-$3K/month for ongoing maintenance. This covers security patches, dependency updates, minor bug fixes, and small feature additions. It's a fraction of SaaS costs and keeps the software current.
Scaling limitations. Mitigated by: proper architecture from day one. A well-built custom application on modern infrastructure (Vercel, AWS, Supabase) scales to thousands of users without architectural changes.
Feature gaps vs. SaaS. This is actually a feature, not a bug. You build what you need. SaaS tools ship features you don't use and charge you for them anyway. A custom tool does exactly what your workflow requires and nothing else.
The Compounding Advantage
Here's what the 5-year view misses: the advantage accelerates over time. Your custom software's annual cost stays flat (maintenance + hosting). Your SaaS costs compound annually. By year 5, the gap is enormous. By year 7, the SaaS tool is costing 2x what it cost in year 1, while your custom tool costs exactly the same.
This is the structural advantage of owning versus renting. And it's why 35% of teams have already started replacing SaaS and 78% plan to do more in 2026. The math doesn't lie.
Want to build a 5-year TCO model for your specific SaaS stack? Get a free SaaS audit — we'll map your highest-cost subscriptions and show you the exact savings timeline for replacing them.