Pet stores are expensive, yeah, but they are businesses. They have huge overheads, there is no money in the pet store business, not if you care about the animals. People (in my town anyways) complain about prices, but when they have a crisis, they come running to us for help. Funny enough, we always end up hearing about how much cheaper we are than Petland. Ordering parts/meds/equipment online is fine, but what happens when you cant wait a few days? What happens when you need something right away, but the lfs went out of business because you bought your stuff online?
It doesn't hurt to support your local economy once in a while.
(that doesn't mean I support over pricing, some places do just charge way too much, but most pet stores can't compete with online pricing)
Edit; on a side note, I agree that most of the fish prices people have been listing here are rediculous. Especially $10 for a convict, we sell them for four bucks.