Staples offers the Trademark Home 300-Foot Remote Control Wireless Doorbell, model no. 72-306P, for $6.99. Plus, Staples Rewards members bag free shipping. (Not a member? It's free to sign up.) That's the lowest total price we could find by $3. It features 32 different chimes and an adhesive back for easy mounting. It requires a 12-volt battery (included) and two AA batteries (not included). Deal ends October 2.