If I were you I would buying a Banana Pi.
Today browsing the forums on bananapi.com I see that the community is moving quite. Although lack of good support in the graphics hardware acceleration, we can see interesting projects soon.
For now, we will have a rPLAY version for Banana Pi (paid) with support for: AirPlay, AirPlay mirroring, and Miracast Chromecast. Video of his performance below...
The price of this software is not yet confirmed but will be around $5-10. Pretty good if they promise what we can see. The big problem of Raspberry Pi is their CPU and can't run Google Chrome decently, so I don't think it will continue its development beyond the beta we have.
The software will run on any version of Android 4.3+.
It will be available on the bananapi.com website and probably I'll get one license.
More info: vmlite.com