Philips Sonicare HX3631/06 PowerUp Battery Sonic Toothbrush for $10.85 after clipping a $4 off coupon as shown in this screenshot.  Shipping is free on orders over $35.  If needed, use this Filler Tool to pad the order for free shipping.  It uses 2 AA batteries (included) and may be more convenient than rechargeable models when on the road.