Even with 10% off, those prices are high (compare with Farmhouse Brewing Supply)... Selection is also small (compare with Rebel Brewer). IMO the brew builder software is extremely limited. Maybe it's good for a complete novice, but it's far too limited for me to even consider. Then again, I just use BeerSmith to make my recipies. It has ALL the ingredients I use (not just what one store sells) as well as my equipment entered into it.
IMO, brewmasters warehouse is a meh vendor. You can get a better selection without much effort. A typical order, for me, from Rebel Brewer arrives in about 3 days time, via ground shipping. Farmhouse is about the same via their standard shipping method. Plus, I've communicated with both of those vendors to make sure things got out in time. Farmhouse gets top marks there. Of course, with my LHBS being Jasper's (
http://www.boomchugalug.com/) I get the yeast I want, and can get most anything else I'll need same day.
No shipping needed. I can even get stuff special ordered (that he doesn't carry/stock) quickly enough. I've had Keg Connection special order things too, with solid results.
Use who you like, but shop smarter. Don't be fooled by software that's supposed to help you out but really doesn't. It's ok for the site (to rough in a recipe) but that's about it. It doesn't replace having good software on hand where you are.