On The House via Amazon offers the Tens Handheld Electronic Pulse Massager Unit for $29.95. Coupon code "H3Z95XNS" cuts the price to $18.27. Plus, Prime members qualify for free shipping. (Non-members can spend $49 to qualify for free shipping; otherwise, shipping costs $5.63.) That's the lowest total price we could find by $2, although we saw it for $2 less in October. It features six auto modes, fully-adjustable speed and intensity, eight attachment pads, and includes eight AAA batteries.

Note that it's unclear whether or not you'll receive four or eight pads and batteries.