Well, at $5.95/cu. foot — round up to $6, multiply by 4 = $24 for 4 cu. ft. That’s cheaper than your $37. One of the bags was broken and I pulled out a little to feel it. It was lovely stuff.
Don’t tell Diana but I’m one of those guys that cuts a slit in bags of stuff to sample the contents. My late sister (one of them) lived a block from a large K-Mart and the garden shop manager would call her and tell her he had some broken bags of amendments and sell them to her “dirt cheap”...
Pro Mix home page. Looks like they have different formulas... http://www.premierhort.com/eProMix/index.htm