ANy snake will drop in value by the time you breed it- that's how the ball market works.

I think your best bet is to get some solid, multi-gene carrying animals and breed them together- you can always sell those, as opposed to single gene morphs that become less sought-after.

Example- you can breed albinos and sell the babies for $150 each in 2 years, or you can breed a ghost pastel to a honey bee and make some sick babies that people will still pay high dollar for.