True plastics dealers can be found in most metropolitan areas. Otherwise you'd need to buy wholesale from a true framing dealer and not some ready-made framing distributor.
Difficult to save money unless you cut the sheets yourself, but plastics shops can give you
a volume rate to do it for you. Plexi type acrylic has several distinct advantage: it doesn't
break easily, it is clearer than glass, and its a better insulator with respect to preventing
condensation behind the glazing. Disadvantages include higher price, easy scratching, and
the need to apply anti-static liquid if you don't want it attracting dust. True anti-reflective
(optically coated) acrylic is very very expensive, but there's nothing quite like it. The amt
of UV protection afforded by any of these products, glass or acrylic, is marginal. Might help
a tiny bit, but nothing will protect color prints well under direct sunlight or hot halogens.