Huge oversized "brick"

[phototec]

considered making it out of 3/8" white cardboard and then printing the brick color and pattern on the flatbed.

It does need to be portable for several events around communities in the area.

I don't think your cardboard idea will hold up to the traveling around part, best bet is one big solid foam block, painted brick red with a a texture paint.

If the cost is an issue, and the Dryvit is out, just get some white textured wall paint at HD, and have them put BRICK RED color tint in it and shake it up for you. Roll the color over the distressed and primed foam block, done!

 

[UFB Fabrication]

White Styrofoam with polyurethane hardcoat sprayed on top. Light strong and durable. BTW bricks with holes are for buildings and paver's dont have holes.

On a second note dont worry about the cost, a decent shipping case lined with padding will be 2 or 3 times the cost on the sign. They will be looking to raise millions so a few bucks for a decent prop should not break the bank.