I think $50 is normal. That's around what the last two vets I've used charge, and they're not in wealthy areas.
That said, I get all my vaccinations through a mobile clinic, so that I can save the vet visits for when there are issues (weight change, behavior change, illness).
here's the clinic:
http://www.luvmypet.com/
I found it saves me a lot of money. I have more than one pet. And the vet charges more for the vaccines, plus a visit charge for each pet to administer.