Hobbykingmall via Amazon offers Prime members the QuadPro Brain Flakes 570-Piece Building Set for $19.99. Coupon code "QUADPRO8" drops it to $13.85. With free shipping, that's $6 off, tied with our mention from two weeks ago, and the lowest price we could find. This BPA-free set includes 570 brain flake building blocks, four wheels, a building booklet, and storage pocket. Deal ends August 16.