Yallstore via eBay offers this 21-Piece Universal Disc Brake Caliper Tool Kit for $18.89 with free shipping. That's the lowest price we could find by $2, outside of the mention below. It enables the rewinding of pistons back into the core on most disc brake calipers and includes right and left hand threaded rewind tools, two pin fixed drives, and 17 adapters.

A close price: Alienbid via eBay has it for $19.55 with free shipping.