I'm always torn between wanting several different tanks with different looks, fish, plants, etc. and wanting to do one tank, but do it up right. If I ever "do it up right" those ADA tanks surely are beautiful. And if you're thinking about something that's going to be a centerpiece in your home, your primary (or at least major) hobby, and a source of joy for years to come, the cost doesn't seem so prohibitive, long-term. A lot of people spend a lot more on a big-screen t.v., a flashy car, or other hobbies than you would spend on a dream tank.
But, of course, there's a place for the $9.99 10 gallons too!