The pink foam strips act as lifts on the roof walls to prevent any insulation from trapping moisture. These "Raft-R-Mate Attic Vent" boards as well as several types of "Roxul" insulation are sold at Home Depots.
The R value per inch for fiberglass insulation is 3.14, Roxul is 4.1, and closed cell foam would be around 5 for the rafter depth we have here. An install of 5" thick closed cell foam in the open ceilings of Christian's old farmhouse cost $3,000; however a partial house install does not work with this product. Spraying foam on old wooden beams, floor boards and electrical wiring seems wrong and too expensive for us besides. Single cell foam would be $2,000 for the same areas with the same issues and an R value of 3.7 per inch.