Lowe's offers the Bosch Impact Tough 24-Piece Screwdriver Bit Set for $9.98. Plus, MyLowe's members bag free shipping. (Not a MyLowe's member? It's free to join. Also, Amazon has it for the same with free shipping for Prime members.) That's $10 off and the best price we could find. The bits feature a black oxide coating.

Update: Note that this item is temporarily out of stock, but can still be ordered at this price for delivery when available.