For those of us lucky enough to live near a Big Al's in Canada, they're having a major tent sale this weekend, October 3rd-5th.
They're also renovating the tanks at the Missisauga location, so 30gal tanks are $15 and 50gal are $40. I'm going to see if my uncle can drive me out there.
...and info about the tanks is on the homepage on the left navigation bar:
http://www.bigalscanada.com/
Some of these stores are TTC accessible!!! Though I definitely wouldn't want to be carrying a tank on the bus...