It's been a while but I am going to be putting down the foam board this weekend. If I am looking at the right stuff, it looks like my local Home Depot has two options.
R-Tech
1 in. x 48 in. x 8 ft. R-3.85 Insulating Sheathing
which is $13.48 per piece
OR
Owens Corning
FOAMULAR 150 1 in. x 4 ft. x 8 ft. R-5 Scored Square Edge Rigid Foam Board Insulation Sheathing
which is $31.32 per piece.
My guess is that the R-Tech is the way to go but can someone confirm for me or point me in a better direction.
Thanks.