The bigger the tank the thicker the glass has to be. Don't know for sure but that could be why the price jumps. If you think glass is bad price acrlic tanks.
However, if you look at it like I do. My husband and I are allergic to pet dander and we can not get our children any dogs, cats, birds, gerbils, etc. We think of the fish as their pets in the future and starting them out young that only makes it more fun as they grow up and get to see the fish grow with them.
Tanks are expensive, but if you compare tanks to what you are putting in these tanks to enjoy them you are actually coming out cheaper by buying the tank once, you will spend more money on getting more inhabitants and more food then you are getting tanks. That is how I put it in prespective with my husband.
I think that tank prices are fine for now...but other pet products are way over priced! didnt you guys notice that? some chemicals you put in your tank is just way overpriced, i think, and so are some accesories(esp the plants, decor, and all those other stuff...
the local glass store (an hour away, local ) sells glass real cheap, 5 pieces wouldn't much at all. I wonder how hard the are to make, probably pretty hard.