Yeah, some people do seem to go the really expensive route with tanks. I try to keep it basic and simple. There are some kinds of fish that are pretty hardy, so we go with them. Some plants, a basic filtration system, regular water changes, and some of our fish have lasted years. It really is amazing how much you can spend though - especially if you go the salt-water route. That is way, way above both my expertise and my budget!
What I may do is build one. My dad built a tank, when I was a kid, and I still have one of the old "everything you want to know about fishkeeping" books from the 1940s. It actually is not difficult to do. Just have to make sure it's properly reinforced or things could, well, explode (for want of a better term!). We recycled a small table someone threw out here, just after we moved in. Had to get a new glass top cut to size for it, and the glass was really cheap (surprisingly so). Might go old-school and build a wooden frame and use nice, plate-glass inserts. The Daughter has always wanted a tall tank - there are some fish that prefer to be near the surface, some mid-way, and then there are the bottom feeders. She has always wanted to have one with like drift-wood in it, and heavily planted, with small schools of Neons and some coreys for the bottom, that kind of thing. Shouldn't be too hard to make like a 20 gallon tank that is taller than usual, and perhaps not as deep front to back.
How to do it and still surprise her with it is going to be the trick.
