Got some glass from lowes, and I have to say it is almost worth the money to go to a real glass shop. The glass that I got from lowes was very poorly cut, they didnt have tools to do anything but full length cuts (I wanted to notch the corners of the lids i was making to make room for air line, etc coming out of the tank), and the cuts were *very* poorly done. I ended up having to use a sanding block to sand off the burrs and chipouts when I got home because they had no finishing tools either.
YMMV, but, Buyer beware.