Cabela's offers its Cabela's Pro Pedestal Boat Seat in several colors (Charcoal pictured) for $4.88. Opt for in-store pickup to dodge the $5.95 shipping fee. That's the lowest price we could find by $11. It measures 6" x 14.5" x 11" and mounts on any standard pedestal or swivel.

Update: Coupon code "7HOLIDAY" yields free shipping.