Woot has the Soundcast Audiocast Wireless Audio System for $49.99 + $5 shipping.

Link

Warranty: 2 Year Soundcast

Features:

* The Soundcast Audiocast lets you turn your PC into a music server.
* Simply hook the Audiocast transmitter to the headphone out jack on your computer and send your recorded music files to the Audiocast receiver that is attached to your music system, up to 350 feet or 150 feet though walls and doors
* You can use two receivers with each Soundcast transmitter so that you can create two separate music zones in your home.
* You can connect two Audiocast transmitters to the same music source – then you can make a four zone system.
* Connects your PC/Mac/MP3 player wirelessly to an audio system that is up to 150 feet away
* Uses 2.4 GHz wireless FHSS technology to send a clear uninterrupted audio signal to the receiver, allowing your music to be accessible from almost anywhere
* 1 transmitter can connect to 2 receivers to create a 2 zone audio system. You can also connect 2 transmitters (connected to the same audio source) to 4 receivers for a 4 zone audio system
* Transmitter is compatible with any device that uses a 3.5mm audio out put jack
* Receiver is compatible with RCA (red and white) connectors
* Bypasses DRM restrictions because you are playing audio directly from your PC, Mac, iPod, or MP3 player
* Has 3 different audio channels to broadcast on
* Dimensions: 6.8×2 x 3.5 inches (W x H x D)

In the AudioCast Transmitter box:

* Transmitter
* Power Adapter
* Audio Cables

In the AudioCast Receiver box:

* Receiver
* Power Adapter
* Audio Cables