What it costs to run your own system in year two

Why there are no figures here

Because any figure quoted without a scope is untrue, and the scope differs every time. Instead I describe the structure of the bill — what it is made of and what pushes each part up. You can take that to any supplier and check whether their quote has forgotten something.

The four parts of the bill

1. Where the system runs

The most predictable part and usually the smallest. For a system serving a handful of people in a company it can fit inside the free tiers of the underlying services — in one of our projects the infrastructure costs nothing while the team stays at five people or fewer. For a shop with real traffic and a catalogue in the thousands it is already a genuine cost, but still one you can calculate in advance.

The thing worth asking: what happens when you pass the threshold. An answer of „we will see then” means nobody has worked it out.

2. The services you pay for externally

Sending mail, a payment gateway, maps, a language model processing text, data from registers. This part varies because it grows with usage — and it is the only part of the bill capable of surprising you.

In the customer service system we wrote about separately, drafting replies costs between tens and a hundred and something dollars a month at over a hundred drafts a day. In a CRM for a broker, pulling company data from the register cost 1.17 złoty for 3,250 records — and we know that figure because it is displayed in a cost panel rather than estimated. An earlier note in the project quoted „two grosz per company”; once measured, it turned out to be dozens of times too high.

3. Changes that arrive from outside

The most consistently underestimated part. A provider changes how their service is connected to, a new reporting obligation comes into force, a shop moves to a different payment gateway, browsers drop support for some mechanism. Nobody ordered any of it and it all has to be done.

An honest project budgets for this up front — as a normal part of a system's life, not as an emergency that surprises everybody on a Friday afternoon. The size depends mostly on how many external services the system talks to. A system talking to mail, a shop and a language model has three potential sources of such change.

4. Fixes and development

After the first months of use it always turns out that some assumptions were wrong, and that some features which took long meetings to agree are used by nobody. That is normal, and it is precisely the value of launching early — you find out after three months rather than after two years.

This is the only part that depends entirely on you. You can set it to zero for a given year and the system will keep running. You cannot do that with the other three.

What is not in this bill — and that is the whole difference

With a custom system there is no per-user fee. Adding a fifth or a fifteenth person to the team does not raise the bill, because you are not buying licences, you are running your own tool.

That is the line item which grows fastest and most painfully with ready-made tools, because it grows exactly when the company is growing. Eight people across three tools at a few tens of złoty per person per month is a sum that becomes serious over three years — and buys you nothing you did not have on day one.

Working out whether it pays for itself

1. Add up the monthly fees for every tool the system would replace — including the charges for extra users.
2. Add the time people lose retyping data between those tools. Hours times rate, per month.
3. Multiply by 36 months — roughly how long a system lives before it needs a serious rebuild.
4. Subtract the build cost and three times the annual running cost calculated from the four parts above.

If the result is negative, we will tell you so in our first reply — because running a system that does not pay for itself is bad for us too. We would rather not have the work than have a client who does the sums after a year and regrets it.

What belongs in the contract so year two is not a surprise

Most disagreements about cost come not from bad faith but from nobody having settled what is included. Four clauses worth asking for:

• Response time for a failure — and separately: what counts as a failure. „The system is down” and „a report looks odd” are two different matters with two different deadlines.
• What counts as maintenance and what is new scope. Fixing a fault in what was built — maintenance. A new feature nobody mentioned before — new scope. The line is blurry, so describe examples rather than definitions.
• Who pays for changes forced from outside. A provider changes how they connect, a new legal obligation arrives. Nobody is at fault and the bill lands somewhere.
• What you get if you part ways. Code, data, access, documentation — in a form that lets somebody else take over. For us that is a design assumption, not a courtesy: a system that cannot be handed over is badly built.

Three signs the running cost is about to get away from you

Nobody knows what the system spent this month

If your only source of information about external service costs is the invoice, you are reacting a month after the fact. A counter in the panel is cheap to build and turns the cost conversation from guesswork into facts.

Every small change needs the supplier

Changing the text of an email, adding a user, correcting a rate — if that needs a ticket and a quote, the running cost grows every month, because a live company generates dozens of such details. Things that change often should be changeable from the panel.

The system talks to more services than anybody has counted

Each external service is one potential forced change per year. With three that is predictable. With ten, running the system becomes a job of its own — and that is the moment to ask whether all ten are truly needed.

Two bills side by side

So this does not stay abstract, take a company with a team of eight.

Ready-made tools: three subscriptions, each priced per user. The bill grows with every new person and with every price rise from the provider — and those arrive regularly and are not negotiable. Add the time spent moving data between tools by hand, because they rarely connect well. The advantage is no build cost and it works from tomorrow.

A custom system: a one-off build cost, then the four parts described above. The bill does not grow with headcount; it grows only when usage of external services grows. The disadvantage is that year one is dearer and that it needs your attention for a few weeks.

Those two curves usually cross in year two or three — which is why the question about year two matters more than the question about the build price. If you plan to use something for a year, ready-made tools almost always win. For five years, they almost never do.