Good call. I don't mean to insult but I have seen more than 1 acrylic disaster. As Pepcrylic said, there is a world of difference between Acrylic and Glass. However, making this large a tank out of glass is going to result in an enormously heavy tank. At the least get a few quotes to have this made out of acrylic. Off the cuff I would guess $5k-$10k or so.
Are you saying that this 400G build, in acrylic, would cost $5,000 to $10,000? Or in glass? Because mine is quoted, it's 150G, and would cost less than $500 for the glass.

