BS23, and a solid body? 15k is a good price. I think the post that said bring 12k cash in hand is the ticket. But here's the thing, if you can spend 20k or a little more, and take your time looking you maybe able to find a way better car that needs alot less work.
I search the internet almost everyday for a dimond in the rough, ebay, traderonline.com, cudaworld.com, google...you name it. The Cudas are out there, and there are people that wake up everyday and say, I'm gona sell that thing, I need the cash fast.
I came across a one owner, west coast rust free 70 340 Cuda original paint car, that I told a friend about. He bought the car for 23k over the phone. Unbeleavable find!