It takes usually several attempts before you hit the jackpot, and then you may never hit it again.
I once found a woman selling all the stash...3 finished tops, many sewn blocks ready to be put together, 9 rulers, fabrics, some on the bolts, stabilizers, scissors, pins, etc and I only paid $32.00. I never again found anything sewing related in a garage sale, and where I lived they had tons of them. Keep trying.