A camp I used to hunt out of had several ground blinds built on plastic pallets with pressure treated 4x4 skids under them. A little lumber and some old metal roofing for the sides and roof worked pretty good. Being able to move them was a plus when the deer's travel routes changed. We would move them with ATVs.
For the sides and roof, I think its hard to beat Coroplast - that plastic stiff they make signs from. Basically plastic cardboard. Comes in colors, different thicknesses (I use 5mm), fairly inexpensive, weatherproof,light (maybe 4 pounds per 4x8 sheet), can be easily cut with a utility knife, attached with fender washers and drywall screws. What's not to like?
