Well, since your budget is pretty low, I don't think you are going to find something that is stronger than plexiglass at a budget price. How big is your robot (length,width,height) ? Also, does everything have to be glass (gears, chains, etc...)? Because, if everything has to be glass, you have to buy custom-made glass which will cost you a lot more money.
just want to make a window like a mech warrior has kind of like the raven but with four legs and and one wheel to each one.or use a construction cab then again trying to keep a hold of how much i can get to get a reliable computer also a 3d imaging system to build this thing i got plan
err. can't help you as much as I would like to... look on Google for a cheap glass-cutting device that you can rent for a couple hours in your location. research up some strong glass material on Google also.