Sears offers the Craftsman 13" Tool Bag, model no. 37535, for $4.99. Opt for free in-store pickup to avoid the $6.50 shipping charge. That's $5 off list, a buck under our January mention, and the lowest total price we could find. (We saw it for $2 less in December.) Bag colors vary by store.
Update: Kmart offers it for $4.49 with free in-store pickup.