first of all, this is one of the huge frustrations I have with BYB. They don't think/ know/ care about potential genetic problems- just stick one dog with the other, bingo, cute puppies, loads of dosh. Every single breed (or designer breed) that becomes popular mysteriously seems to present more and more commonly with skin problems/ other defects, which I can't help but assume is down to people with no actual deep interest/ knowledge in the breed pumping out puppies. These kind of breeders will NOT be remotely prepared to take the dog back, because to them it was a financial transaction, and they don't really care (unlike proper breeders, who would be horrified to discover problems in their lines)
having said that, as atopy is SO common in dogs these days, it would be a disaster if everyone who owns an atopic dog gave it up! Vet bills are, unfortunately, one of the issues of owning dogs, and should have been factored into your decision to get a dog, really. Think yourself relatively lucky- there are other conditions that cost even more, and any dog can become unwell.
I'd say follow some of the advice above, and speak to your vet about possible treatment options. these cases are frustrating and difficult for vets and owners, and uncomfortable for the dog, but the aim is to manage rather than cure the condition, and it can take a while to get it right. Good luck