I just came from Homedepot and a 4x50ft roll is 130 bucks. They only had 1 kind but different sizes. It could be pretty expensive,. They also had 4x8 sheets of Styrofoam stuff with foil on one side for 12 bucks a sheet. I think I'd rather use the hard sheets vice the roll, or the best option would be spray foam, depending on cost.
Let us know what you decide.
Don't sweat the petty things; Pet the sweaty things !!!