Huh I am kinda surprised you are doing that with a PS3. When I had PS3 I simply vacuumed the vents once a month and would see no point in opening it unless the heat-sink malfunctioned.
I think at the end of the day it wouldnt be worth getting all that done to it. Id just buy a PS4 instead personally with all that money.
I have not heard of any places that do this but just be wary as some companies even geeksquad has been caught pretending to do work on it when they didnt in reality, as a scam.
