Made these for my 4x4 box blind last weekend. Windows are 10"x38".Used an acrylic sheet from Home Depot that cost $36. It cut pretty well. 2x2 wood frame with Titebond III wood glue and plastic screen window clips that way I can change out the windows when they get bad or add tint if I feel like it. They still have the protective plastic on them. I think they turned out pretty well.
Total cost for all 3 was about $60.