Basics
What Makes a TYPO3 Project Expensive or Cheap
Naming a figure before knowing the project would be guesswork. What can be said seriously is which factors push the effort up and down, and where you have influence yourself.
Why flat rates mislead
TYPO3 gets used when requirements go beyond the standard. That is exactly what makes flat rates worthless: two projects on the same system can differ several times over in effort without either being badly costed.
Quote a figure anyway and you have to make assumptions. Usually it turns out later that they did not fit, and then the unpleasant phase of change requests begins.
What pushes the effort up
Custom content elements. Every element of your own needs configuration, a template and discussion. Ten elements are a different project from three.
Languages. A second language does not double the work but does increase it noticeably: translations, language links, edge cases where content has not been translated, and a separate sign-off for each language.
Several domains in one installation. Technically an advantage of TYPO3, and in the project additional coordination, because what the sites share and where they differ has to be settled.
Interfaces. Connections to a CRM, an ERP or a merchandise management system are rarely the standard case they are described as. The effort sits less in the connection itself than in the behaviour when something fails and in the coordination with the system on the other side.
Existing installations. Taking one over costs understanding first. How much depends on whether the code is documented and versioned.
What brings the effort down
Clear decisions. The biggest avoidable cost is not technology but indecision. Overturn a structure three times and it gets built three times.
One contact who can decide. Rounds of discussion where nobody is allowed to decide lengthen projects reliably.
Fewer variants. Four well-considered content elements carry a site better than twelve that overlap. Fewer variants means less building, less testing, and an editorial team that finds its way faster.
Content on time. Copy and images are the real bottleneck in many projects. If they exist before the building starts, a whole loop disappears.
The costs after the project
What regularly goes missing from quotes is running the thing. A TYPO3 installation needs maintenance, regular updates, and at some point an LTS jump.
Those items will certainly arrive. Thinking about them in the first plan is more honest than a low opening figure with an unpleasant surprise standing behind it two years later.
How a dependable estimate comes about
It starts with a conversation about what you have in mind and, if there is one, a look into the existing installation. Out of that comes a breakdown by area with ranges rather than point figures, and a note of which assumption sits behind which range.
The advantage of that form: when an assumption changes, it is immediately visible which part of the estimate is affected. That is what makes it possible to steer deliberately during a project instead of being surprised at the end.