Since you called it rigid board foam, it sounds like you didn't buy the white beaded foam (like those cheap foam coolers) that gets extra messy when you cut it. Other than the foil and plastic barrier on it, which sounds like it might be peeled off, it's probably fine for scenery. The price sure was good.
That's nice that the store cut the foam for you. I usually take my four-foot straight edge, a measuring tape, and a snap-blade knife with me to the store and cut the foam in the parking lot. Last weekend, I cut up a 4' x 8' piece of 2" foam into four 2' x 4' pieces to get it home in my car. Easy peasy.
DFF