>Yes, you're right. Do you have any idea how can i aproach this problem?

My expirience is that if you make a good prototype with a lot of the functionality your customer asked you about, you can defend dropping some specific feature that could cost too much or delay the project.

As usual, customers want it all with bells and whistles done for yesterday. If you show a good product (or prototype), and you explain them that that particular feature could make the product more complex to install and mantain, and it can delay the project due to added research needs, they tend to undestand.

But... show them something cool first. It's not the same thing explaining the features you would NOT include before you show them the ones you actually do.

Best luck!