I'm still planning on using foam insulation for my shop.

I had a conversation with my neighbor, works in construction, and he told me it would cost $40.00/linear foot. He was basing this on a 2x4, but my shop was constructed with 2x6.

Since close cell foam insulates on the order of R6-7/inch, 5.5" would be around r33 - 49.

Is that cost reasonable or is he off?

My shop is 30'x28'x10'. ACtual framing is 8', as the first 2' are concrete block.

Thanks,

Louis