I replaced my seized up compressor with a rebuilt one I bought for $90 shipped on ebay. It has worked great for a couple months so far.
If you get one from the yard make sure that the center piece turns freely (not just the pulley) and I would flush it out good with fresh oil.
It's not too bad of a job to do if you have a free day, especially for the money saved. Make sure you flush everything out while you are at it and replace the drier as well.
I had to replace my transducer as well, which most likely contributed to destroying the original compressor.
With the car off, try turning the center piece on the compressor, see if it turns smoothly or not. There should be some resistance, since you are turning the insides, but it should be fairly smooth.
Last edited by 94Beater; 09-04-2012 at 01:57 PM.