Recharge with a can of UV dye, then find the leak that's causing you having to recharge? Could be as simple as an o-ring. Hopefully...
The compressor went out in my '93 GMC. Bad bearings. Firestone said $1,200 to replace it. I didn't even bother with the dealer, but expect them to be the same, if not more. I changed it out myself, along with the orifice tube and accumulator, for ~$350 in parts from local auto parts store. Then charged with an R-134a conversion kit. Never had a problem with it again for the next 10 years I owned that truck.
I wonder if the a/c recharging systems that shops use are in fact better since they pull a vacuum on the system and purge it of atmospheric air?