i've always wondered if i would work for a petco if given the chance (highly doubt it now that college is almost done)...but i kinda thought about it and realized that you won't be working exclusively with reptiles all the time...theres stocking the shelves and bla bla bla bla...but it comes with the job ya know? if you can deal with that, then go for it.
Not all Petco's are terrible. i've been in a few that had excellent upkeep. You're knowledgeable and know what's required. You can certainly start to work there and educate people and be one of the "good ones"
but keep this in mind...there are ok snakes at Petco, and then there are gorgeous snakes online from reputable breeders. Don't get caught telling people to look online. you may lose your job for that. silly? yes. but it's a business.