Thumb Score: +11

Leatherman tool group via Amazon [amazon.com] has for Prime Members: 21-Piece Leatherman Double-Ended Screwdriver Bit Kit for Multi-Tools on sale for $20. Shipping is free.

Product Description from Store:[LIST][*]21 double-ended bits = 42 total bit types in two compact flat sleeves[*]Flat bit design: standard hex-bit performance at half the size