Try your local freecycle... that is where I got mine... for FREE! woo-hoo
I just posted a request for a tank and gear... and a lady just happened to be moving and didn't want to move the tank. I also got some other stuff too. 2 Filters, 2 air pumps, a heater and a gravel cleaner from a different person. I don't know what I can use yet, but I'll just freecycle whatever is left when I'm done with set up.
I can't really set it up until summer.... but we went
driftwood hunting today and found some cool things.
Good luck finding a tank!