In short: start with a SaaS (a ready-made subscription tool) when your needs are standard and you want to be operational immediately, with low upfront cost. Move to custom software when your processes are specific, the per-user fee gets heavy as you grow, or you need integrations and control the SaaS can't offer. Many companies start on SaaS and build custom when the off-the-shelf tool starts costing more than it returns.
| Criterion | SaaS (subscription) | Custom software |
|---|---|---|
| Upfront cost | Low (monthly fee) | from €2,000 |
| Cost over time | Grows with users and features | Fixed one-off + maintenance |
| Time | Live immediately | Weeks / months |
| Customization | Limited to built-in options | Total, on your processes |
| Ownership and data | The vendor's | Yours |
| Best for | Standard needs, quick start | Specific processes, scale |
A SaaS is a ready-made tool you use by paying a subscription: CRM, invoicing, project management, help desk. The advantage is immediacy — you're up and running the same day — and near-zero upfront cost. It's the right choice when your needs fit the market standard and you have no unusual processes. The limit shows up with growth: the per-user fee multiplies, and you adapt to the software, not the other way around.
A piece of custom software is built around your real processes: it does exactly what you need, integrates with the tools you already use and keeps your data yours. The upfront investment is higher (from €2,000, and from €5,000 for a full ERP), but you pay no growing per-user fee and the value lasts. It's the right choice when the way you work is a competitive edge no off-the-shelf tool reflects.
Do the math over the medium term, not just the first month. Add up the SaaS fee for the number of users you'll have in two or three years and compare it with a custom project paid once. If your processes are standard and small, SaaS wins. If they're specific or you scale fast, custom pays off. Tell us how you work and we'll run the honest numbers together.