Coming from corns, I know what you mean. Ball python morphs are outrageous! However... if you buy some normals or cheap morphs with the hets, you could make a pretty penny...

*quits dreaming about money*


But I know what you mean. I think you're best bet would be to go to a reptile expo. Some vendors at those are selling amel and snow corns for super cheap (8-12 bucks), so I can imagine you'll be able to find BPs for cheap if you look hard. You would also be able to examine the snakes in person, which is an amazing thing to be able to do. A well tempered snake may be completely different to you than to the person you're buying from.