You need to take a drive to see Dennis Olthoff in Mt. Ulla, NC (about two hours away from Raleigh). Dennis is very well known in the Superformance (SPF) world.
You will be able to see different cars and test drive a few, as well. It looks like he has several used SPFs on his website that are in your price range.
http://www.olthoffracing.com/
Good luck.