Custom build vs vertical SaaS TCO in New York in 2026

The verdict in three sentences

Under 15 users and a standard need, the vertical solution almost always wins over 5 years. Beyond 25-30 users or with strong business-process fit, custom becomes profitable and frees you from vendor dependence. The real trade-off is not the entry price but the 5-year TCO plus strategic dependence.

The entry cost in 2026

Custom software is a one-off, amortisable investment plus annual maintenance. A vertical SaaS is a recurring subscription that grows with your headcount. The two models have very different cash-flow profiles.

The 5-year TCO by user count

The number of billed users flips the equation. At 80 EUR/user/month, each tranche of 10 users adds 9,600 EUR/year to the SaaS, i.e. 48,000 EUR over 5 years — enough to fund part of a custom build.

Tipping point and dependence

In this example, the tipping point sits around 20 users over 5 years. But cost is not the only criterion: custom removes the risk of vendor price hikes and service shutdown, provided you take on maintenance.

Mini case study

Claire is CFO of a 34-person industrial SME in New York. She is evaluating a vertical ERP at 95 EUR/user/month for 30 users, i.e. 34,200 EUR/year. Over 5 years that is 171,000 EUR. A custom build fitting her processes is quoted at 72,000 EUR plus 12%/year maintenance, i.e. 115,200 EUR over 5 years. The 55,800 EUR gap and the vendor independence decide her toward custom — especially as her production processes fit no standard.

FAQ

From how many users is custom profitable?

As a 2026 order of magnitude, beyond 20-25 users billed at 80-100 EUR/month, the 5-year TCO leans toward custom. Below that, the vertical solution stays cheaper and faster to deploy.

Does custom really cost 8-18% maintenance a year?

Yes, that is the realistic range for fixes, evolutions and security. Underestimating this line is the classic mistake: unmaintained software becomes costly technical debt within 2-3 years.

What happens if my SaaS raises prices?

That is the main risk of the vertical solution: a 15-20% hike applies to your whole user base. On 30 users, +20% is nearly 6,800 EUR/year more, with no recourse.

Can I start on SaaS then move to custom?

Yes, it is a prudent strategy. You validate the real need at low cost, then invest in custom when volume or specificity justify it. Plan your data export from day one.

How do I secure the business fit of a custom build?

A 5-10 day functional scoping (4,000-8,000 EUR) with your operational teams sharply reduces drift risk. It is the best investment to avoid software that does not match your processes.

Let's scope your project. Give us your headcount, critical processes and budget, and we will jointly compute the 5-year TCO of custom versus your vertical solution. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.