OG, you're right, the actual parts are inexpensive. I was wondering how much the tech. charges to actually install it and if anyone on this site had had it done. I guess the best thing to do, obviously, is to make some calls.
OK, the cost is $70, but that also includes the guy coming to my apartment to pick up the computer and take it to his shop and to return it and plug everything back in once he's installed the new part.
The problem is that when I go to switch it on in the morning I have to press the button multiple times before it finally comes on, so I decided to get it replaced before it gives up altogether.