If someone wants to buy a crossbreed, then I think that's fine, because obviously they'll know that it's mixed if they ever breed or sell the animal (or offspring) they can state that it's crossed as well. Just makes sure you go to a good breeder that states if the snake is pure or not. I got my girl at Repticon.
Some people don't like crossbreeding, other's don't mind it. So it's really up to the buyer on what they want.