There is one good and bad thing about fish keeping. A lot of people get into it, kill a bunch of fish, then get out. This is bad as they probably didn't get good advice and got burnt. But the good side is you can pick up cheap tanks pretty much whenever you want. There are always tanks available at low prices, you just need to look around. If you are planning ahead and taking your time, you can get lots of good bargains.
And you have to buy some things online. Filters and stuff cost way too much at many LFS.
And we have 2 large canisters on our 220l / 60g goldfish tank. The one (oversized) filter wasn't enough even though they are small at the moment.