Have you seen this one on Criagslist? Blue vert with white top. According to description its very original. Noticed he dropped the price 2k from where he started.
What concerns me about the $18K one on craigslist is the messed up bumper. I've read stories on this site about the China-made nightmares. And many other things need a lot of refreshing. Engine, Trans leak, interior, dash. It all adds up fast. This one is totally ideal to me - also with AC... http://www.haggleme.com/Vehicle/71968/1968-Pontiac-Firebird.aspx but fairly steep price for only having a 350 V8. IMHO.