Unless you are getting the glass for free, it isn't worth it. I have built a number of tanks, because I got the glass for free. They don't have top or bottom frames. In fact I would be surprised if you could buy the glass for the cost of a ready made tank. Of course, a used one is cheaper again. During boxing week, Big Al's was selling 55 gal
tanks for $59.99 Cdn, and 75 gals for $89.99. I don't think you can beat that.