So I guess the answer to my question is essentially "you pay for them like everyone else!" Haha!
What is the stores plans for these guys? To sell them or to breed them? If you're planning to sell, I strongly recommend getting in touch with the breeder to confirm what they are, since you don't want to risk mislabeling them. As someone above pointed out, if the possible fire/OD snake is really a desert female, trying to breed her could get her killed. Unless the reason why they were donated is genetic uncertainty to begin with? Even finding out the genes of their parents would be helpful because we'd be able to make educated guesses at least.
If you plan on breeding, you will have more chances of proving them out correctly. It might not be a bad idea to pair them with the genes we suspect they have, to confirm by producing supers. So for example, pairing a possible firefly with a fire/super fire and getting a super fire hatchling. And if they're all pastels as well, you'd see if it was a super fly, etc.
No matter which way your store decides to go, keep in touch! I'm sure I can speak for all of us when I say we'd love to know what they turn out to be (and whether or not your store ships because those guys are hooot!)