Pastels are more common than other morphs and because of that, there end up being more -pastel x whatever- paired with a -pastel x whatever- and the super pastels are the goal of the pairing, they're a by-product and therefore not as valuable. With the bumblebee versus the mojave x spider, there are more but it's because bumblebee is such a cool name, a marketing thing. New breeders get into this and want to produce that cool sounding morph combo.
There is nothing attractive about a mojave spider advertising wise, it's very plain. The day it starts being called a javabug or something like that is the day it will compare in price to a bumblebee or super pastel.
That game is the DEVIL! And the fact that you would compare the auction house there to the snake trade is...is...not right!