Personally I would take the animal back to the breeder and get my money back.

However you should make a decision quickly because the snake should be treated as soon as possible. I have aquired 2 snakes that came with mild RI (no visible mucus, slight weezing) I took them to my vet and for about $30.00 each the animals where treated and recovered very well.

Ultimately the decsion is yours but if you decied to keep the animal the injections are pretty easy to give.