i'm going with 2 windows each will be 8'x3.5'x1" i called the local plastic place and 2 1" thick 8x4 panes would be just over $2kIt's price could very greatly depending on what size arylic sheets you use in that I have asked one place for a eight foot wide four foot high two inch thick sheet and it came out to $1300 and I would have two or three of those lined up next to one another. So that alone would cost $5000 dollars depending on if I use one of them or two of them. I did once ask this one arylic company and they said that a ten foot wide three inch thick section that is six feet tall would cost $20,000 while another company said to me it would be $15.000 for a giant sheet of arylic of the same size in that they both would have to be custom made. But the 4 foot high eight foot wide sheet is a stardard made sheet size which is why they are much cheaper then the big ones. So any giant tank idea wide a limited buget would have to use the eight by four foot sheet as the biggest sheet of arylic on it.
Now for the cement work and cinder blocks I think I would set at least ten thousand dollars for in that I would make the fishroom it's own sperate room from the existing house to prevent water damage to the house from the heat and water from the heated fish tank.