Custom software cost: what it really costs you

The cost of custom software development looks scary at first glance, especially next to the entry price of an off-the-shelf tool. The problem is that this reflex compares a one-off fee with a monthly subscription without ever putting them on the same time frame. Here’s how to do the maths properly, line by line.

The scary price, and what it leaves out of the comparison

A business owner receives a quote for custom management software. The figure at the bottom of the page looks hefty, especially next to a subscription advertised at a few dozen euros a month on a mainstream software vendor’s website. The natural reflex is to stop the comparison there.

That reflex compares two things that aren’t alike. The custom quote covers a scope agreed in advance and unlimited usage rights, often with no cap on the number of users. The subscription, on the other hand, goes up with every user you add and every module you switch on, and it keeps landing every month, including the year when nothing changes in the business.

The mistake isn’t choosing the off-the-shelf tool. It’s comparing a price shown for one month with a price shown for the whole lifetime of a project. The right question isn’t which option costs less today, but which one costs less over the same number of years.

What an ill-fitting off-the-shelf tool costs over three years

Here’s one way to set out the calculation, with assumptions stated openly and adjustable to your situation. Nothing here is a client figure or a costed promise: it’s a simulation, to be redone with your own amounts.

The amount almost always missing when people compare on instinct is the “time lost on manual workarounds” line. An off-the-shelf tool that doesn’t quite fit the business gets worked around with a spreadsheet on the side, data entered twice, a double check. That’s the line that changes the final result, and it’s the one the next calculation puts a figure on.

What the gap between the tool and your business costs you

The method is the one I use to size every project: time lost per week on a task, multiplied by the fully loaded hourly cost of the person doing it, multiplied by the number of weeks worked in the year. Three variables, one formula, no magic numbers.

An estimate to give you an idea: thirty minutes lost every day on avoidable re-entry of data, for someone costing twenty-five euros an hour fully loaded, five days a week, forty-seven weeks worked. The calculation gives an annual order of magnitude which, added up over three years, often exceeds the price gap shown between the two options.

What drives the price of custom software

Three factors explain most of the price gap between two custom software quotes for similar businesses.

The functional scope matters most: a tool that handles a single task costs far less than a system covering a whole process, from the initial request to invoicing. The second factor is integration with your existing tools: connecting the new tool to accounting software, a CRM or a messaging app takes time if the data flows aren’t already documented.

The third factor, often forgotten when the first quote comes in, is annual maintenance, usually a fraction of the development cost, to be planned from the scoping stage rather than discovered a year later.

It’s this scoping work, before a single line of code is written, that separates a well-run custom software project from one that spirals. It sets the exact scope, the integrations needed and a realistic maintenance load, before the budget is fixed.

What goes wrong, and how to avoid it

Where to start if you’re comparing yourself

Four steps before asking for a quote, custom or not.

1. List the tasks involved, the ones that come back every week and take time because of an ill-fitting tool.
2. Time a real week, not an off-the-cuff estimate: measured time almost always differs from how long it feels.
3. Compare both options over the same period, three years for example, including licences, add-ons and workaround time for the off-the-shelf tool.
4. Ask any custom software provider for a quote broken down line by line, with scope, integrations and maintenance listed separately, never a lump sum with no detail.

Frequently asked questions

What is the minimum price of custom software for an SME?

There’s no universal floor: the price depends on the functional scope you choose, not on the size of the business. A tool that handles a single, well-defined task costs far less than a system covering several areas of the business.

Is custom software always more expensive than an off-the-shelf tool?

Not when compared over the same period. A subscription that goes up with every user and every module often ends up costing more than a one-off fee, once three years of licences are added up.

How much does custom software maintenance cost after delivery?

It’s negotiated before signing, as a percentage of the initial development cost, and you should ask for it explicitly rather than discover it a year later on an unexpected invoice.

At what company size does custom software start to make sense?

It’s less a question of size than of frequency: as soon as a task comes back every week and no off-the-shelf tool handles it without a workaround, the question is worth asking, whatever the size of the team.

How do you stop the budget spiralling mid-project?

By agreeing the scope in writing before you start, and by treating any request added along the way as a separate, priced work package rather than a free adjustment.