Sears offers the Irwin 6" Locking Clamp with Swivel Pads, model no. 18, for $8.05. Opt for in-store pickup to avoid the $5.99 shipping charge. That's tied with last year's mention and the lowest price we could find by about a buck, outside of the deal below. It features a guarded release trigger, wide-opening jaws, and an alloy steel construction.
Of note, Shop Your Way Rewards members will earn a Sears credit with this purchase and may be eligible for additional credits and discounts.
Update: Amazon offers it for the same price for Prime members.