Richard,
I have a shop, Acrylic Imagery, and you can talk with us at the NJ frag swap. But its doesn't even come close to being worth it for you to do it yourself. You might save some money but if your considering doing it yourself to save then you can't afford to mess up those sheets. And there is a huge difference when your making a tank for someone else and if you mess up you can cut it down and still use material, versus doing it once for yourself and having to get it right the first time or eat the money. And you have to make sure it holds water for the duration of its life while being in your home. If you bust a seam, who are you going to be angry with. Even though people don't say this, if the seam isn't right or the tank thickness is too thin then the tank can come apart. The good thing is you can see it coming but its still going to be upsetting. If I was a diy'er I would do it in glass, way way before I did it in acrylic, because the gluing process is much easier. But then you have to deal with the weight.
If you had said I want a 2'*2'*2', I still would have said something similar but it would've been a more acceptable lose for you. But a 5' x 3' x 2' is a larger tank and it will be very big for you. I could easily say I can get cut sheets for you and I could make money off it, but thats really not in your best interest. The money you think your saving, you won't save in the end. Shops don't get rich off of one tank, its a business like any other. Whatever you decide goodluck with it.
