Well, you are mostly paying for the time to recap the console. Depending on the caps used they can be fairly inexpensive. But the process is just a little tedious. It takes some time to go through and decap the board, then clean the entire thing in a washer or with rubbing alcohol and q-tips then put all the new caps on. It gets even more expensive if using ceramic caps.
Imo $75 for a full recap is fairly cheap as well on these systems as anyone that fixes them needs to go through and fix any other issues caused by the caps. Bad/broken traces, destroyed op-amps, possible bad 7805's etc.
A standard recap may not fix most boards because of issues caused by the old leaky caps.
This is just my 2c as most boards I have recapped I had to do other stuff to them to figure out where the bad traces were etc.
But, imo, anyone mentioned in this thread is very capable of repairing the systems. I am a bit less known for doing it but I do offer the service on my site.