Screw messing with plexiglass windows. Buy some cheap vinyl slider windows from Lowe's. You can get them for about 40 or 50 a piece. It will get the steepest investment in the house, but it's worth it. Having windows you can't open or that make noise or don't keep out weather will ruin a well built shooting house. Don't skimp on the windows. And if I had to do it again, I'd use a treated wood floor instead of regular plywood.

I painted the outside with Lowe's barn paint. Hunter green, barn red, and black are fine colors for the deer woods. It's not cheap paint, but I'm building for a couple decades of use. Seal up the inside with great stuff and some good caulk. I put a stall mat in mine instead of carpet, it works great, but I'll take it out after the season because it's already holding moisture under it, hence why I would have gone with a treated floor.