A best bet is the 96-Piece Diamond Ice Cube Tray (pictured) for $4.99 before the above coupon, $3.74 after. With $4.60 for shipping, that's $14 under the lowest total price we could find for such an item. It allows you to make 96 diamond ice cubes at once. It ships in a random color; you don't get to choose.
Expect these items to take two to three weeks to arrive.