A/C condensor

As you can see from previous threads, my van has many problems. I received it used. Anyway...The air conditioning does not work, it blows out hot air. I had a mechanic check it because I thought it just needed freon. Well...he told me that it needs a new condensor, freon, etc. His estimate was around $800. Does that sound right? My question is can a used condensor be used or should a new one be purchased?

PS: The heater works well, if that makes a difference?!

I recently changed the A/C condenser and main compressor lines on my 95 Windstar. I first tried a used condenser from a wrecker, but it looked as bad as the one that came out, so I turned it down and went with a new one. Doing the labour myself saved big bucks - all I paid for was the parts (condenser is $250 Canadian $) and the recharge. Best of all - it works :)