I paid full price for mine at a pet store. Now wondering whether I should have bought one somewhere else. I'm a newbie to fish so I didn't really know where else to buy one. For my next tank (I have multiple tank syndrome already!) I want to make sure I know the best place to get one.

Petco $1 sale, craigslist, other online ads or newspaper ads, small mom and pop shops, second hand stores, charity stores, there's a lot of places to get cheaper tanks from. The Petco $1 sale and Craigslist are your best options but keep an eye out for tanks wherever you go. While walking my dogs I've even found a couple 10/20 gallon tanks that my neighbors put out to the road.