REI Garage offers the Serfas Seat Bag Combo in Black for $28.73. Opt for in-store pickup to dodge the $5.95 shipping fee. That's $31 off list and the lowest price we could find. It features a ballistic nylon bottle cage, 15 function super tool with inflator, tire levers, 8-piece patch kit, and two threaded 16g C02 cartridges.