Yep you got taken pretty hard. IMO the probing fee should just be part of the physical exam fee. The float fee is insanely high. For what they did the total should not have been more than around $50-$60 and I think that is even a bit high. Take it as a lesson learned. Find a new vet in the future, and only take him to the vet if he is sick. There is no need for checkups on ball pythons. I hope the vet was one of the few that actually knows something about reptiles at least. Good luck with your new snake. You might want to try to find a breeder in your area. Becoming friends with a good breeder will do you and your snake far more good than going to a vet (and it's free).