Dpends on where you live. I can get the bulk stuff from auto glym, 25 L and gallon stuff. Not every product though.
Canadian Tire sells Autoglym in Canada. Different stores carry different products though (some sell almost the whole line while others only sell a few) The are almost always on sale though
Anyone herd of a site called TCP Global (www.tcpglobal.com)? They seem to be the people selling Autoglym products on Amazon. I found it to be cheaper to buy Autoglym products from their site than Amazon (me being from Canada). They also carry 3M, Menzerna, Raceglaze, etc but don't know if they're cheap for those.