Try Chard56, he has all the bettas under the sun, plus some. Plus, they're purdy, lol.
Check aqua bid and look for auctions that say mustard gas - thats what that coloration is called. Might cost you a pretty penny, though.
Maybe this one from aquabids?
http://www.aquabid.com/cgi-bin/auction/auction.cgi?fwbettashm&1374864713
blackwater bettas she breeds that kind just ask her she on face book.
Most of these bettas are $20-$30, plus shipping.
Yeah, I noticed. That's what I'm trying to avoid :/ I saw some beautiful ones at Petco too! And the most expensive was like $12. I think I am going to buy one from Petco