Teensy v3.1 MK20DX256
About
Teensy v3.1 MK20DX256 OSH Park Edition.
Price
17USD out of shipping costs.
Lsusb
Depending on whether or not you press the reset button, the VID/PID is different:
zoobab@sabayon /home/zoobab [21]$ lsusb | grep 16c0
Bus 006 Device 004: ID 16c0:0486 Van Ooijen Technische Informatica Teensyduino RawHID
zoobab@sabayon /home/zoobab [22]$ lsusb | grep 16c0
Bus 006 Device 005: ID 16c0:0478 Van Ooijen Technische Informatica Teensy Halfkay Bootloader