The verdict in three sentences
Buy when the need is standard, non-differentiating and covered by a mature SaaS; build when the software carries your competitive advantage or when SaaS cost explodes at scale. The right arbiter is neither the sticker price nor the trend, but the 5-year TCO crossed with business specificity and lock-in risk. In 2026, the answer is often hybrid: buy the foundation, build what sets you apart.
The decision matrix
Four criteria settle 80% of cases. Rate each axis from 1 (low) to 5 (high): the more it leans toward specificity and scale, the more build is justified.
| Criterion | Leans toward BUY | Leans toward BUILD |
|---|---|---|
| Need specificity | Market standard | Unique, differentiating process |
| Scale (nb users) | Low or moderate | High (cost/user explodes) |
| Competitive advantage | None (support) | Core business |
| Required integrations | Existing connectors | Custom, proprietary systems |
| Data control | Acceptable in SaaS | Sovereignty / strict compliance |
| Time-to-market | Immediate required | 3-9 month margin acceptable |
The 5-year TCO: the deciding argument
SaaS appeals with a zero entry cost, but its recurring cost grows with users. Custom software has a heavy upfront investment then a low marginal cost. Here is a 2026 order of magnitude for a tool used by 60 people.
| Line item | SaaS (60 users) | Custom |
|---|---|---|
| Upfront investment | 0 EUR | 110,000 EUR |
| Recurring cost yr 1 | 43,200 EUR (60/mo) | 18,000 EUR (maint.) |
| Recurring cost yr 2-5 | 43,200 EUR/yr | 18,000 EUR/yr |
| 5-year TCO | 216,000 EUR | 200,000 EUR |
| Vendor lock-in | High | None |
| Customization | Limited | Total |
At 60 users and 60 EUR/user/month, custom overtakes SaaS by year 5 while removing lock-in. Below 20 users, SaaS is almost always more cost-effective.
Mini case study
Mehdi, CIO of a retail group in Casablanca, equips 80 managers with a SaaS CRM billed at 70 EUR/user/month, i.e. 67,200 EUR/yr. Over 5 years: 336,000 EUR, not counting paid modules. A custom CRM aligned to his processes is quoted at 140,000 EUR + 22,000 EUR/yr maintenance, a 5-year TCO of 250,000 EUR. Savings over 5 years: ≈ 86,000 EUR, plus the end of lock-in and native integration with his ERP.
FAQ
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Is SaaS always cheaper at the start?
Yes, its entry cost is near zero, making it unbeatable to test a need. But from 40-60 users, the per-seat cost often ends up exceeding an amortized custom build.
What is lock-in and why is it risky?
It is dependency on a vendor: price hikes, costly migration, trapped data. In 2026, a 15-30% SaaS price increase in one year is not unusual.
Can both approaches be combined?
Yes, it is even the norm: buy the standard blocks (mail, payroll, accounting) and build what differentiates you. This is composable architecture.
How do we estimate the tipping point?
Compare annual SaaS cost × 5 to the custom TCO (build + 5 years of maintenance). Build becomes profitable when that total exceeds the upfront investment plus maintenance.
Is custom riskier?
Only if poorly scoped. Incremental delivery and an MVP validate value before the heavy investment, bringing risk down to SaaS-project levels.
Let's scope your project. Give us your number of users, your current SaaS cost and your differentiating processes: we produce a costed 5-year TCO build-versus-buy comparison. 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.
