Funds to build these systems are raised at IndieGoGo, the goal was set at $80,000 and it already stands at $129,790 with still 65 hours left. You can check out the project over here and buy your own Pi-Top Kit for $285.
While it's a neat concept, the price is definitely a bummer. The minimum price including shipping comes in at $320 and for that amount you can definitely get much better laptops. HP for instance has its Stream laptop series with pricing starting at just $199.99 for the 11.6" version and 229.99" for the 13.3" model.
Other components of the kit include a Raspberry Pi with three expansion modules (laptop power management PCB, HDMI to LVDS bridge PCB, and keyboard+trackpad controller PCB); a 13.3-inch LCD panel with HD (1280 x 720 pixels) resolution, a battery, a USB 802.11 b/g/n + Bluetooth 4.0 WLAN controller, a keyboard and trackpad, a DC wall plug, and a piece of paper with a URL to an online video tutorial on how to put the thing together.