More depressing is that your faith that it's a spider has caused you to put up blinders to the input of objective (they didn't sell you the snake) experienced breeders. I personally would not pay 'retail' price on a snake that wasn't a perfect indisputable example of a given morph or combo. At that cost, I would probably seek out the input of some other breeders before buying and would decline if there was doubt. Regardless, if you enjoy your purchase and he's now healthy that is all that matters. Good luck proving out whatever genetics may be there.