Overstock.com offers the Sennheiser On-Ear Wireless Headphones, model no. RS120, for $56.99 with free shipping. (Amazon charges the same.) That's the lowest total price we could find by $12, although we saw them for $2 less in December. These open-back headphones feature a wireless transmitter that acts as the headphone charging dock. It includes two AAA NiMH rechargeable batteries.