$900 is pretty typical for a pet store. They have to make a profit over the original price, and the snake takes up display they could use for another animal. So they usually mark up.
EDIT: I'm not saying I would pay that much, unless maybe it was some kind of magical unicorn pied that pooped rainbows. And I give the price tags in my local pet store the stink-eye every time I walk by them. But that is about what they are selling pieds for right now.