Walmart offers the Schumacher 300-amp Jump Starter, model no. XP2260, for $99.98 with free shipping. (Amazon and Home Depot charge the same.) That's the lowest total price we could find by $40. It features 300 cold crank amps (1,200-amp peak), two 12-volt accessory outlets, 150 PSI air compressor, USB, and digital display.