I've been following this thread since it started and up until now decided not to post because I wanted to view it with more of a level head. In reality, NONE of us will ever know what exactly happened to the OP's BP until he gets a necropsy done by a qualified Vet. To the OP, if going to a Vet is too expensive for you, try a local Vet school, they tend to not charge as much since it's a learning facility. That will be your only 100% for sure way of knowing what happened. With that said, there may be a chance that the Vet/Vet Student can't find anything wrong, that it was just your BP's time to go. I am very sorry for your loss, and I can't imagine how hurt and disappointed you must be for this to be your first actual hands on experience with a snake. From the information that you gave us, it sounds to me like the Breeder was exercising good customer service by offering to give you another BP for free, and even going an extra mile to pay for your ticket to the show. As for the $50.00 shipping cost, that is about normal for shipping a live animal. When I had my spider BP shipped to me, it cost me $66.00 for shipping. Also, we don't know if that particular breeder is set up to ship based on the fact that a lot of us have never heard of this guy, and if he had given you the information that he -could- ship, that info was also not shared with us. Also, some breeders will refuse to ship live animals in cold weather. This isn't to antagonize you or to 'punish' you, it's for the safety of the animal. Could he ship it? Yes. But no matter how many heat packs he throws in with the snake, with the weather being how it is in the winter up north, it's not realistically possible to ship a 100% health guaranteed snake during this season.
I hope everything goes well with your new BP, and if you have any other questions/concerns about him, feel free to ask