I corresponded with one local shop, and for the Marineland 30x30x24 93g cube without the "Corner-Flo"--just the basic tank, they quoted me a price of $560. That seems a little steep for a 93g tank. Hmm, I think I need to make a few more calls this weekend. I know there will be a place eventually who can order and sell one for $450 or under. I have a few months to shop, save, and think about options. I know I could get a larger, standard size tank for $400 or less, but [language filter], having a 93g cube would be cool.
Edit: I also looked at the tanks at glasscages.com, but the reviews of that business have scared me away. I'm also going to touch base with Envision Acrylics with regard to making one, but I'm thinking they will be too deep for my pockets. Envision seems to make dynamite tanks, though, and they are right down the street from me.
I saw an ad about CB's Tropical's tanks on Craigslist a couple of weeks back. Are they out of business? I still have a pleco that I bought from them in my 75g cichlid tank, and he is still going strong 15 years later. It was a nice shop.