I do both. LFS is not always over priced. Blake's throws out some really good prices. The coral reef has good prices as well & a great selection. Better prices on common stuff, but I've found some very cool pieces at tcr that I never see online.
Also prices from most reputable online vendors, are generally in line for the most part. I've found the better the deal, the better the chance of getting ripped off. Aka mr.coral or reefs2go
Dry goods, I use drsfoster Smith almost exclusively. No one matches their selection/price/shipping. Very seldom do I need to look elsewhere. But salt, Blake's for red sea all day.