TomTop offers the Meterk DK-BL 1,500-milliwatt Laser Engraver for $125.99. Coupon code "E2100" drops it to $89.99. With free shipping, that's the lowest total price we could find by $40. It features Bluetooth 4.0, USB, and engraves wood, plastic, rubber, and leather.
Note: This item ships from mainland China and may take two to six weeks to arrive.