Heres a suggestion you could try for getting acrylic: Try a glass cutting place, they might have some acrylic scrap, since they also use the acrylic for windows. Lowes is another place to look for acrylic or plexiglass sheets.
My father just happens to work for a place that makes acrylic, so when it came down to me needing a sheet of acrylic, my dad came to the rescue. He found a full sheet of acrylic that was thrown in the trash dumpster because it had a defect in it. Which I found out a moth had flown onto the acrylic sheet when they were placing down the protective film on it and the moth became a fossil.
Try places that make acrylic and ask if you could take some of the defective sheets. If you wonder, why would I get an defective sheet? Just to let you know, if a foreign particle lands on the acrylic when they lay the protective film or making the Acrylic, they must discard the sheet to the trash.
So in theory, you could get a whole sheet with one small defect in it and still come out with material you can use.