We build something similar uing lexan and aluminum framing. It is 7 foot high, 8 foot wide, and four foot deep. For water we put a hard shell pond liner with a filter and fountain. It works great.

The only issue might be snout rubbing since the walls are transparent. This was not a big issue for us for some reason.

300 dollars is a heckuva lot cheaper than the one we built. Looks like a great deal to me.