You can purchase a pair of Sennheiser RS120 wireless headphones from Amazon, eBay, Best Buy, Overstock, Newegg, Tiger Direct, Radio Shack, and Zzounds. The cost is around $100.00
One can purchase Sennheiser rs120 headphones off of Amazon, Newegg, and other electronic superstores such as Best Buy. There are many other varieties of Sennheisers on these websites also.
Headphones that sound the same as Beats but relatively cheaper are Sennheiser HD 202 II Professional or Sennheiser RS120.
RS120 926 MHz Wireless RF Headphones:The Sennheiser RS-120 includes one set of HDR 120 headphones and a TR 120 transmitter, but additional headphones are available for purchase. The transmitter can transmit to any number of headphones, as long as they are all set to the same frequency. While the transmitter has an RCA-type input, it includes two adapters that allow it to use 1/8″ or 1/4″ connections as well. This allows it to accept input from any number of sources: computers, TVs, MP3 players, stereo systems, and more. With so many possibilities, you will find uses you had never thought of.