I don't know anyone that just collects snake morphs. People that have more than a few snakes tend to also breed. If not for profit then to recoop the cost of getting what they wanted or t get what they really wanted by buying the ingredients for it.
I am breeding to recover the money invested and to get my sought after pieds.
So if I really wanted a desert, which I don't, but if I did, I would be breeding to get the money to by a desert since it is a base codom which I can't afford outright.
So to the OP's point, since desert females aren't breedable (as evidence has shown so far) they are about as valuable as a normal male.