Only works w/ power supply.
$125 shipped, paypal, OBO
It has velcro on the bottom and I don't know where the battery door is.
I have replaced all 4 switches with soft touch switches that are directly soldered to the circuit board rather than the spring loaded crap switches it comes with.
The new switches don't "click" like the stock ones. They simply respond when you tap them without the need for additional pressure to make them "click." Much more responsive and reliable.
See this video for what I'm talking about. I didn't use it for my project, but it's the same parts/idea: http://youtu.be/aEDBrT63khQ