Where to find canine vaccines in Northern Virginia?

I recently moved from Mississippi to Northern Virginia, and am wondering where to find vaccines nearby. Back in MS, we would go to the local co-op for distemper/lepto/bordetella vaccines, then get the annual exam done at the vet when we went in for the rabies. The dog park we have been going to has had a distemper outbreak, and even though we are showing no signs I want to be able to booster my dog's immunity just in case. Does anyone know a place in the Chantilly/Fairfax/Herndon area that sells these vaccines besides a clinic? Its like 8 bucks tops for a vaccine at a farmer's coop, where its about 20 bucks at my clinic, plus an office visit fee, plus an exam, which adds up to about 50 bucks for one vaccine, yuck!