This is so true... it's part of the risky/vague return policy thing. A breeder will give you up front detail instructions on what to do if your animal is sick upon arrival and what they will do about it.
Petstores, using my local petco for example will only pay for vet bills if the animal is taken to one of their approved vets within a limited amount of time. If you take the snake to any other vet first they will not cover costs and it's not their problem anymore.