A lot of factors at play here.
Rarity is one reason. New morphs come out, everyone wants them. Ball pythons can demand such a high price simply because the market for them is bigger than any other reptile, everyone wants in on the “next big thing” and everyone wants to make the next big cash out on breeding.
For animals like leachies, you’ve got to consider how they bond. You can’t just throw two leachies together and then breed. If I remember correctly they’re a species that basically bond and breed for life. This makes getting an actual breeding pair much harder, and a lot less people breed them. I think there’s roughly 500 leachies for sale on MM, vs 46k ball pythons.
Another thing to consider is # of babies provided per clutch/year. Some species produce very few babies per year, while others throw a lot of babies out. That’s why you see ball Python morphs drop significantly in price year over year. The market gets flooded eventually.
Supply and demand plays a huge factor in all of it. Not everyone wants to breed leachies, so they’re much less being produced. While it seems everyone and their brother breed ball pythons.
I’m sure you’ll get some other great feedback, but that’s my initial thoughts this Monday morning.
the biggest thing is demand. if a morph nobody wants to work with (lets go with pastel) then the price will go down and won’t be as expensive as a morph that is popular and has been out for a while (lets go with clown). If a new clown combo, lets go with a clown pied for simplicity, comes out the production will be very low and the demand very high. so when more of the same combo comes out than it may still be a 10,000 dollar combo because of that demand. If a worlds pastel pied comes out, it may only be 1,000 dollars as the demand for pastel combos isn’t as high.
Adding into the convo that @logar added above… the type of genes st play matters also. Double/triple/quadruple etc. recessives will fetch a much higher dollar than animals that are Inc. co-dom or dominate morphs. They’re much harder to produce and the odds of hitting some of those combos is astronomically low.
When it comes to crested geckos, I believe a lot of it had/has a lot to do with heritability, at least up until recently, though I think it still affects the pricing to some degree - Before 2020 pretty much only axanthic and lilly white were considered “genetic traits” or whatever people called them, basically the only two that were proven, so the prices of those two genes were sky high.
Since the knowledge of the their genetics is still so new and not super widespread, we still see that with cappuccinos and such, even though they are already mass-produced.
Any “new” gene is likely gonna be pretty pricey at least until the next one shows up.
Other than that, having the name of a well-known breeder tied to the gecko definitely hikes the price up a lot as well, even though the quality isn’t necessarily any better than geckos from someone with no name.
Ive personally found what i would consider pretty high quality animals for cheap from “just wanna try it once” breeders, who didn’t know anything about morphs or traits.
Also geckos that can be tied to well-known lines are usually quite a bit more expensive like charcoals or confettis, as opposed to normal black phantoms or red/white/black spotted phantoms.
Structure also matters a lot when it comes to cresties specifically, geckos with nice structure are often worth a lot more than geckos with bad structure, regardless of their genetics.
And of course just demand and trends in the hobby. Some morphs are pretty consistently popular, whereas other’s popularity changes over time.
One thing I have not seen mentioned is the breeder business ethics. Most sellers are just that. They sell their animals and wash their hands of it.
Then you have the top teir breeders that you can call up any time of the day and go over husbandry issues with 12 months down the line and will spend an hour or more out of their day helping.
Some have full teams/families dedicated to making sure that their customers are always happy. Which costs extra.
Heck, one seller recently sent a snake to someone who has not even purchased from them before simply because the one they initially inquired about had sold. For free. Shipping included. It fit their plans they had discussed, and they wanted to be remembered as a top-notch business.
Honestly, there are some real real good guys out there and they absolutely deserve to be charging much more than the others.