I bought the cheap closed cell insulation that I saw last week at Menards for $8 something including taxes. I will write what's on the package below.

BASEMENT WALL INSULATION: covers 4'x8'area (32 aq. ft.) with furring strips-6pieces: 1 1/2" x 14 1/2" x 48". RayLite expanded polystyrene insulation (ESP) is a lightweight closed cell, rigid insulation, that has excellent long-term thermal and moisture resistance. RayLite is a very versatile material useful for new construction. remodeling, hobbies, packaging, whatever your imagination can dream up. RayLite is a very workable product that can be cut with a knife or saw and sanded or shaped easily.

It sounds good.
John