I'd go mail order with it. The only thing I'd buy locally would be a C12k that looks like it has stretch marks on it if you can find one at woodcraft.

We don't have lee valley B&M stores here, though. I'd probably buy stones they have as their selection of waterstones is a bit more up to date than woodcraft or rockler, and their prices better.

A lot of the kitchen stores are going to have private label kind of stuff that's marked up a lot from the brand stamp of the actual manufacturer (for example, if you get a naniwa stone, they may private label something for wusthof, who will add another 50% to the cost).