Mike, charcoal is always available somewhere, thank goodness. At least, that's my experience in the DC area. Costco only carries it seasonally, but when I got my WSM in January, Home Depot had plenty of 48 lb packs of Kingsford, plus bags of hickory wood. Even a few grocery stores (large and small) had some, tho alot of times it shares space with fireplace logs in the winter.
That being said, I picked up 144 lbs of the stuff today just to feel good about saving a few bucks, and to be ready for the next month or so of grillin' and smokin'! Woulda' bought more, but I don't have the space to store it...