So I got my official quote for spray foaming the cabin. It is a 24 x 28 with 10 ft sidewalls and 12/12 pitch roof.
This is for open cell foam.
3-4 inches in lower walls. $1,400
3-4 inches in gable end walls. $ 390
5-6 inches under roof deck. $1,950
5-6 inches at band board. $ 225
So just about $4,000. That's a bit more than I expected. I'm not sure what blown in would cost but I think I need to check.
Went through a similar exercise on our place, ended up buying a 2 part mix 600 board foot foam kit for $700, applied approximately an inch foam under the roof deck and gable ends and placed R40 12 inches of fiberglass batts under that. Used 1 inch closed cell foam sheets on exterior walls and another 6 inches(r20 ) between interior studs. Very happy with heating and cooling performance and this ended up being probably at least 60% cheaper than all spray foam application. Keep sensitive that no matter where you put closed cell foam it will act like a vapor barrier, so plan appropriately.