I live in Rolla, MO. I have had some small luck with auto dismantlers and heater cores, etc.. but they aren't very effective for cooling as they don't allow much air flow.
The recycling center here was great.. lots of condensor coils, etc.. even had some copper plate, thick walled copper pipe in like 2" diamater (lots of it.. exciting
. and many, many large, LARGE bails of what looked to be magnetic wire.... WOW
I think my condensor coil was 9 pounds, so it was $9.