BBEVS are a little expensive (but very good, they're my vets, I highly recommend them!) -- a standard check-up will set you back around $90, and that's without meds or any extras. All the vets (Deb, Melinda, Sasha) are very good with cavies, they know their stuff. They also don't offer payment plans in house. Deb at Camp Hill Vet is also very piggy savvy and she's much cheaper, she's probably the most affordable cavy savvy vet on the southside. On the Gold Coast Green Cross Oxenford (Ryan) has a good reputation for guinea pigs, as does the Gold Coast Vet Surgery (Kevin). I'm not sure about how expensive they are though.
All these vets work with guinea pigs, but I would lean towards Deborah Pears at Camp Hill if you're concerned about price. But, yes, vet visits can get expensive! I've spent thousands over the years in vet bills. It just happens.