The form-fitting controller is made to plug into the Lightning port on a newer iOS device and features console-style controls including a directional pad, shoulder bumpers, and face buttons. It also allows for headphones to be connected through an included adapter, and also leaves the volume up/down buttons, ring/silent switch, and power/sleep button of an iOS device fully accessible.
Logitech's controller includes a 1500 mAh battery which will charge an iOS device whiile it is plugged into the controller, and can also be charged simultaneously with a device through the controller's micro-USB port.
Complaints about the high price tag of the MFi controllers and issues with build quality, could be causing poor sales of the devices, which is the likely impetus for the two price drops.
Update: Logitech has reached out to MacRumors to clarify that the price drop is only temporary, and the price will rise back to $100 on February 1.