Really? That must be new.....I bought one sheet from Regal plastics near the airport
try
Nationwide Palstics
2001 Timberlake Dr
Arlington, TX 76010
Phone: 888-477-0851 / 888-477-0851
Fax: 214-239-3871
I ended up finding it at Plast D Fusers in Carrollton. He has one 4x8' sheet left right now. http://plast-d-fusers.com/ I would give them a call if you need it. 972.620.0555
Yeah I was very hesitant to use any type of paint. Salt water is very corrosive so I didn't want to deal with it flaking off even if it cured inert. I was able to find some locally so I wanted to let people know about this other source that was out there.
I ordered from Aquarium Specialty a month ago, and got a 2' X 2' piece for 12.95. My order was over 175, so it was all shipped free. It was packed really well, too!