Try locating plastic fabricator or supplies in the yellow pages. I have limited local suppliers so i bought a clear 8mm thick piece less than A3 for $29.00 although faricators and suppliers are cheaper usually. The cost of fuel and time to get from a fabricator turned out more, so I ended up getting it from Bunnings.
I found mine in the metal gate section, but things might be a bit different over east.
I bought an A3 2mm sheet for my 8" scope's lightbox from Acrylicsonline on Ebay, they have a 1220 x 610 x 3mm sheet on Ebay for $62 with free postage via courier. Mine arrived in 2 days and did the job perfectly. Here is the description if you want to take a look.
Acrylic Solid White Perspex 1220 x 610 x 3mm Cast Sheet Solid white UV Resistant
If you use the yellow pages you will find a heap of acrylic/poly carb ect suppliers. There nearly everywhere well with in fair distance, well around most industry areas. I found sourcing metal for piers alot harder as most suppliers will only sell in 6m length though after 9 phone calls i now have a source for anything cut to order even 1" thick plate at a fair price. You really need to use the yellowpages for things like this because if you dont shop around you can be ripped off bad.
OK, located a plastic supplier in Castle Hill http://www.hillsplastic.com.au/. Got a sheet of milky 3mm perspex for $30. Tried Bunnings first, but they only seemed to have clear or patterned stuff.
Geoff
