I know I'm late to the party, but I thought I'd through my two cents into the wishing well for anyone who is interested.

The final deliverable is definitely something that should be clearly stated in the scope of work portion of your contract. If the client wants to add to the scope of work at the end of the project, then a new contract should be signed by both parties and it should involve an increase to the final price.

I have never personally had a client request a map with all the layers preserved. But I understand why you would be hesitant to turn something like that over, especially since I only use textures I have created myself. As has been stated before though, a client likely isn't trying to get their hands on your textures so they can use them themselves. More than likely they don't care about the textures themselves...and even if they did end up using them for some reason is it ultimately worth losing sleep over?

If a client wanted my original file with layers preserved and it was clearly stated in the scope of work and their license for usage, then that's fine. As long as they understand that means the price will also go up dramatically.

- Josh