At this point, we have an idea of what the client wants, what really matters, and what we are using to build the solution, i.e. eZ publish. What we don't know is how we are going to implement the solution within the eZ publish framework. But that won't stop the client from asking how much it is going to cost (in the case of internal projects, the question is more likely to be how long). The reality is we can only make a guess of how much it will cost, we can only make an estimate. When it comes to estimations, we need to understand the language we are using and the games people play in coming up with estimates.
Estimates are often wrong.
The accuracy of a particular estimate will depend on the experience of the team, the client, and the complexity of the task.
A task will take as long as it takes, regardless of what estimate is given.
We can't accurately state how long something will take unless we have done it before, under the same conditions.
The bottom line is we can...