There are TONS of neat ol' Buicks on craigslist! Here's another '65 GS: http://www.craigslist.com/eby/car/67436502.html $13k, obo in California.....
Another on Evil Bay http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=4543933387&category=16124
I've got one that I am going to be putting up for sale, but am having trouble coming up with a value, as I am not very knowledgeable about Buick Muscle. It is a factory air car, which I believe that you were not interested in. Quick Info: 65 GS 131k 401 (27k on rebuild) St-300 Air PB bucket seats/console protecto plate I am located in New Mexico