[BobNovas]

Michael - from the lara tools site - lara.com -

In order to purchase these bits you will need to sign a letter stating that you are an authorized serviceperson for the equipment where TORX Plus® tamper-resistant screws are used. Bits are $9.50 per bit and we will also charge you a one-time $20 non-refundable fee to process all the paperwork to authorize you to purchase these bits. The bits will be shipped directly to you from the manufacturer within 5 business days.

This is apparently a requirement that the TORX manufacturer (Textron) puts on the distributors and what makes the fasteners "tamper proof".