The verdict in three sentences
A vertical SaaS costs between 20 and 50 EUR per user per month in 2026 (12,000 to 30,000 EUR/year for 50 users), while a custom application requires 40,000 to 120,000 EUR upfront plus 15%/year maintenance. Break-even lands between 3 and 4 years depending on headcount. The decision isn't only about price but four criteria: process specificity, vendor lock-in, data reversibility and total cost of ownership.
Total cost of ownership over 5 years
Comparing a subscription to an upfront investment requires reasoning over several years. Here is the total cost of ownership (TCO) over 5 years for 50 users, with a SaaS at 30 EUR/user/month and custom at 70,000 EUR (15% maintenance, i.e. 10,500 EUR/year).
| Year | SaaS 30 EUR/user/month (50 users) | Custom (build + maintenance) |
|---|---|---|
| Year 1 | 18,000 EUR | 80,500 EUR |
| Year 2 | 18,000 EUR | 10,500 EUR |
| Year 3 | 18,000 EUR | 10,500 EUR |
| Year 4 | 18,000 EUR | 10,500 EUR |
| Year 5 | 18,000 EUR | 10,500 EUR |
| 5-year total | 90,000 EUR | 122,500 EUR |
At 50 users, SaaS stays cheaper over 5 years. But the trend flips as soon as headcount grows or SaaS prices rise (often 8 to 12%/year). At 100 users, SaaS would exceed 180,000 EUR over 5 years, well above custom.
The decision grid: four criteria
Price is just one of four criteria. The table below helps you decide based on your situation.
| Criterion | Favors SaaS | Favors custom |
|---|---|---|
| Process specificity | Standard process | Highly specific process |
| Headcount | Under 30 users | Over 60 users |
| Vendor lock-in | Acceptable | To avoid (strategic) |
| Data reversibility | Not critical | Critical (own the code) |
| Time to deploy | Immediate | 2 to 4 months |
| Changing needs | Stable | Frequent and unique to you |
In short: SaaS for a standard need, small headcount and fast rollout; custom for a differentiating process, large headcount and a data-control requirement.
Mini case study
Claire is CFO of an industrial SME in Lyon with 65 staff. She uses three separate SaaS tools billing a total of 2,400 EUR/month (28,800 EUR/year), with processes worked around by Excel exports. Custom development unifying these tools is quoted at 85,000 EUR plus 12,750 EUR of maintenance/year. Over 5 years: SaaS = 144,000 EUR (before price hikes), custom = 85,000 + (4 x 12,750) = 136,000 EUR. Beyond the financial gain, Claire eliminates double entry (estimated at 20 hours/month) and becomes owner of her tool, an asset in case of acquisition or regulatory change.
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FAQ
At what headcount does custom pay off?
Generally beyond 60 users over a 5-year horizon, or sooner if the SaaS raises prices sharply. Below 30 users, SaaS is almost always cheaper.
Isn't SaaS safer since the vendor maintains it?
Maintenance is included, but you depend on their roadmap and pricing policy. Custom makes you owner of the code and its evolution.
What happens if the SaaS vendor shuts down or changes terms?
You risk a costly migration. Data reversibility must be checked in the contract: it's a key criterion favoring custom when data is strategic.
Can you combine both approaches?
Yes. Many SMEs keep standard SaaS (payroll, email) and build custom only for their differentiating core business.
How do you estimate total cost of ownership?
Add up, over 5 years, subscriptions (with annual increases) for SaaS, or the build plus 15%/year maintenance for custom. We provide this calculation in every quote.
Let's scope your project. Give us your headcount, current tools and how specific your processes are: we'll cost the comparative SaaS vs custom TCO over 5 years. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.
Mohamed Bah
Fondateur, Kolonell
Passionate about digital and entrepreneurship in Africa, Mohamed has been helping Sénégalese businesses with their digital transformation since 2020. Founder of Kolonell, he believes every SME deserves a professional and accessible online présence.
