The verdict in three sentences
Comparing two systems on sticker price is the first mistake: the real comparator is the 5-year TCO, covering integration, training, maintenance, hosting and exit cost. For SaaS the dominant item is the recurring subscription that grows with users; for custom it's annual maintenance (15-25 % of the build). The curves cross depending on user count and horizon: beyond a threshold, the cheaper option flips.
The 5-year TCO line items
An honest model adds far more than the license. 2026 order of magnitude, EUR:
| Item | Business SaaS | Custom |
|---|---|---|
| License / subscription | 30-90 EUR/user/month | 0 |
| Initial integration | 8,000-30,000 EUR | included in build |
| Initial build | - | 40,000-100,000 EUR |
| Team training | 2,000-8,000 EUR | 3,000-10,000 EUR |
| Annual maintenance | included | 15-25 % of build |
| Hosting / infra | included | 1,500-6,000 EUR/year |
| Exit / migration cost | 5,000-20,000 EUR | 3,000-15,000 EUR |
Worked example: SaaS at 50 EUR/user vs custom at 60,000 EUR
For 25 users over 5 years:
| Scenario | Year 1 | 5-year cumulative |
|---|---|---|
| SaaS 50 EUR/user (25 users) | 15,000 EUR sub + 15,000 EUR integration = 30,000 EUR | 90,000 EUR + 15,000 EUR = 105,000 EUR |
| Custom 60,000 EUR | 60,000 EUR + 12,000 EUR maint. = 72,000 EUR | 60,000 EUR + 48,000 EUR maint. + 12,000 EUR infra = 120,000 EUR |
At 25 users, SaaS stays cheaper over 5 years (105,000 vs 120,000 EUR). But at 45 users the SaaS subscription rises to 27,000 EUR/year, or 135,000 EUR over 5 years: custom becomes the economical option. The break-even here sits around 33-38 users.
The line items everyone forgets
Four costs systematically underestimated in comparisons:
Need a professional website?
Kolonell builds websites that attract clients, optimized for the Sénégalese market. Free quote in 2 minutes.
| Forgotten item | Typical impact | How to control it |
|---|---|---|
| Exit / reversibility cost | 5,000-20,000 EUR | negotiate full export in the contract |
| Version upgrades / breaking changes | 3,000-10,000 EUR/year | realistic maintenance budget, automated tests |
| Third-party integrations (API, connectors) | 4,000-15,000 EUR | map the IS before signing |
| Internal time (admin, tier-1 support) | 0.2-0.5 FTE | include it in TCO as person-days |
Mini case study
Claire is CFO of an industrial SME in Lyon, 40 users. The SaaS rep quotes 48 EUR/user/month, or 23,040 EUR/year, without mentioning 18,000 EUR of integration or 0.3 FTE of internal support (about 15,000 EUR/year loaded). Her real 5-year TCO: 115,200 EUR of subscription + 18,000 EUR + 75,000 EUR of internal time = 208,200 EUR. A custom build at 90,000 EUR + 20 %/year maintenance and the same internal time totals 213,000 EUR: near parity, but with code ownership. She demands the full calculation before deciding, and negotiates the SaaS exit cost.
FAQ
What horizon should I use for TCO? Five years is the standard for business software; that's when recurring costs reveal the real winner. A 2-year horizon mechanically favors SaaS.
How do I estimate custom maintenance? Budget 15 to 25 % of the build cost per year, depending on complexity and pace of change. A stable system trends toward 15 %, a fast-evolving one toward 25 %.
Does internal time really count? Yes, it's often 0.2 to 0.5 FTE overlooked. Valued at 45,000-60,000 EUR/year loaded, it can flip a comparison.
Is exit cost negotiable? Absolutely, and the best moment is before signing. Demand a full data export in a standard format and a guaranteed timeframe.
At what user count does SaaS lose? It depends on the per-seat price, but often between 30 and 40 users over 5 years. Run the numbers with your real figures.
Let's scope your project. Send us your volumes (users, integrations, horizon): we'll build your 5-year TCO spreadsheet with hidden items and a custom quote. 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.
