I used to have a spray foam business ( sprayfoam installation contracting ) and for itty bitty jobs, they were fine, but the cost of the product from TigerFoam was quite high. It did , however, cut down our labor cost, mobilization, etc. ( again, for small jobs) In other words, it has it's place.
Closed cell bio based is right about $ 1.25, installed , but there will be a minimum charge to some degree. Open cell is about $.45 / Bf.
Just for an example this kit is just shy of a buck a Bf.
Quick Cure Two-Component Polyurethane Foam – Class 2 Building Material
Item # TF605 This kit comes complete with 15 ft Gun/Hose Assembly, 6 FAN/4 CONE Tips and kit preparation instructions, but PLEASE read Operating Instructions
& FAQ PDF
This kit has a theoretical yield of 600 board feet (square foot at 1") or 50 cu. ft.
Shipping weight per kit = 120lbs *ships in two boxes
Price $565.00 Qty
The " Kits " we dealt with came on a pallet, 2 - 55 gallon drums ea. The next set up was in gaylords which were a pain to move around. What it comes down to , is that pricing is relative to packaging LOL