SweetLF via Amazon offers the SweetLF Sonic Electric Toothbrush for $29.99. Apply coupon code "6Y3IGEPN" to cut that price further to $18.89. With free shipping, that's the lowest price we could find by about $18, although we saw it for a buck less during Black Friday week. It's waterproof and features three brushing modes and a smart timer. Deal ends April 19.