Over half the neutrals I'm cutting are for the sashing I have planned. Figuring 40" usable fabric, that works out to 16 squares per wof, and you need 400 for 10 sets of 10, that works out to 25 wof strips. With some newer fabric, you may only get 15 squares per wof.
I pulled 17 fabrics, so cut 3 lengths of each one, plus I had enough scraps from three other fabrics so each of my block sets will have 2 of each of the neutrals.
My plan is to make sashing to turn the blocks into 4x4 so I can sew them together and have a checkerboard look.