Generally this isn't so much a question of breed as it is of heritage. Cats who have a long pedigree of top show winners in their background can be thousands of dollars. Otherwise some expensive breeds may be the furless varieties (sphynx, peter bald, minskins) which are usually around a 2K a head in my area. Also some of the newer first generation wild cat hybrids (Bengals, Bristol Cats, Chaussies, Savannahs, Safaris, Jungle Bobs, Machbragal, and Punjabi) can be right up there. There's someone selling Asheera Cats for thousands of dollars but I think it's just a scam, up pricing some of the hybrids and maybe crossing a few to create them.