A friend of mine was looking into this, he had a set of junk stock wheels off his Vette, I think they said about $10-$20 per wheel. I know it depends on where you're at, seems to be higher prices out west.
Try seeing if the local scrap metal place has an email (how we found out from Pacific about the rims), or try to call em tomorrow.
More than likely going to be dirty aluminum due to probly having clearcoat and/or paint; probly 20-25lbs each. Let them know that info and see what they say.