A/C Compressor locked up

What is your question?

Recently bought a '91 740 4 door with AC. Shortly after we bought the car, it started blowing fuses which in turn prevented the car from being shifter out of park. It turned out that the shifter lock button button is on the same curcuit with the A/C compressor. The A/C compressor is locked up for reasons yet to be determined, (though age is probably the real culprit). Once we unplugged the A/C compressor, the shifter (and the car) was operational again. Unfortunately, repairs to the A/C were estimated at an amount that nealy exceeded what I paid for te car and I connot bring myself to spend that much mony on a ~20 year old car. Anyone have any ideas or sources for an inexpensive repair of the A/C?