$300?!?!I'm glad I don't have that vet!
I think it's time to call around to different vets! If there aren't any other exotic vets I town, wouldn't a regular vet be able to do the fecal test? I believe the testing process is the same, and you don't actually have to bring your frogs in (just a fecal sample). It might be worth at least calling around to check if anyone else can do it.