I just bought a Buckeye Field Supply 75 gph RO/DI unit. $250 shipped with all the fittings to hook up to the water supply. Some info:
http://www.reefcentral.org/forums/sh....php?t=1280759
I think lugging RO water from the store will get old really fast, especially when you need to do a large water change to solve a problem.
I think at least one fish store in Calgary uses conditioned tap water (maybe it was just a rumor). It might be an option though I suspect not many people would recommend it. Are there any tanks of the month from Calgary using tap water?