The verdict in three sentences
Vertical SaaS (Pennylane, Sage type) starts in 2 to 4 weeks for 55 to 80 €/seat/month, but you pay that rent for life and customisation stays bounded. Custom costs 40,000 to 75,000 € over 3 to 5 months, with no per-seat cost and no vendor lock-in, but it is a project to steer. The right choice hinges on four variables: file volume, mission specificity, CAPEX/OPEX trade-off and tolerance for vendor dependence.
The decision grid, criterion by criterion
This is not a "good/bad" match but an alignment with your profile. 2026 orders of magnitude:
| Criterion | Vertical SaaS | Custom |
|---|---|---|
| Entry cost | 55-80 €/seat/month | 40,000-75,000 € |
| Time-to-value | 2-4 weeks | 3-5 months |
| Cost per new seat | +55-80 €/month | 0 € |
| Customisation | Limited to options | Full |
| Integrations | Vendor catalogue | Free, open API |
| Lock-in / reversibility | High | Low, you own the code |
| Accounting model | OPEX | Amortisable CAPEX |
No column is better in the absolute: a standardised, hurried firm leans SaaS, a specialised, long-term firm leans custom.
Which profile for which choice
To decide, project your situation over three years. 2026 estimate:
| Firm situation | Recommendation | Main reason |
|---|---|---|
| < 8 seats, standard missions | Vertical SaaS | Time-to-value, low risk |
| Strong growth (+3 seats/yr) | Custom | Per-seat cost eliminated |
| Highly specific missions | Custom | Full customisation |
| Cautious cash, no CAPEX | Vertical SaaS | Smoothed OPEX |
| Wants to own the tool | Custom | Reversibility, asset |
| Needs open integrations | Custom | Open API |
Many firms end up hybrid: SaaS for payroll or document management, custom for production and the client portal, comparing cost module by module.
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Mini case study
A managing partner in Dubai runs a 10-seat firm targeting 20 within three years. On vertical SaaS at 70 €/seat/month, he pays about 8,400 €/yr today but 16,800 €/yr at 20 seats — nearly 38,000 € cumulative over 3 years, owning nothing. A custom core at 60,000 € plus 18 % maintenance runs to about 92,000 € over 3 years — pricier short-term, but with zero per-seat cost and a reversible asset. Over a 5-year horizon at 25 seats, custom moves clearly ahead: his decision is a bet on growth, not a simple price calculation.
FAQ
Is vertical SaaS really faster? Yes: 2 to 4 weeks time-to-value versus 3 to 5 months for a build. If the need is urgent and standard, that is a decisive advantage.
Does custom create an asset? Yes: you own the code, amortisable as CAPEX, and you are not hostage to a vendor. That is a key argument beyond 15-20 seats.
Can you migrate from SaaS to custom later? Yes, provided the SaaS offers a full data export — which is why reversibility must be checked before you commit.
Is the hybrid approach common? Increasingly: custom core for production, SaaS bricks for peripheral functions. TCO is then compared module by module.
How do you avoid vendor lock-in on SaaS? Demand a reversibility clause, a documented export format and a data-return deadline written into the contract at signature.
Let's scope your project. Describe your target headcount, your specific missions and your CAPEX/OPEX preference: we build your costed SaaS-vs-custom decision grid. 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.
