I saw a banner ad on here for maltbuythebag.com, and they seem to have pretty good prices - cheaper than my LHBS's for big sacks of base malts, even when shipping is taken into account. The only question is the quality of the grain.
I'm thinking seriously about purchasing 55lb of the Ireks Munich, but I can't find out any information about them *at all*. It appears they're based in Germany, which is probably a good sign. Maybe they just don't sell much over here?