Thousandshores via Amazon offers the Dr.meter 12-Piece Diamond Drill Bit Set for $14.99. Coupon code "JPI9S52H" cuts it to $9. With free shipping for Prime members, that's $11 off, $3 under our April mention, and the lowest price we could find. These diamond dust-edged drill bits come in 12 sizes, ranging from 4mm to 50mm, and are designed for cutting tile, glass, counter tops, and more. Deal ends October 31.