Butters, whether it's a captive bred snake or not, whether it's a dog or a cat or a bird - keeping animals equals occasional vet costs. To expect that you'd never have a vet cost because a snake is captive bred is fooling yourself.

I think you fed far too soon and far too big after the last regurge, which is likely what triggered this one. Are you absolutely sure this snake isn't being handled too much after eating? Are you sure your temps are correct so that this snake can digest fast enough before the prey inside it starts to decompose?