Busboy,
Check ackits.com for the prices of some of these items. For my '83 pickup, the accumulator is like $17, the condenser is $109, the compressor is around $200 and the evaporator is prob close to $200. They sell an o-ring kit that is $6. If you want to do this work yourself, you'll want to convert to R-134, so either flush your compressor and reuse it or get a new one. The old R-12 will have to be professionally evacuated. Also you'll need a vacuum pump to remove all the moisture from the system when you get it all hooked up.

83 4x4, 3" Lift, 33" Buckshot Mudders