The price of this Wagan Battery Jumper with Air Compressor drops from $109.95 to $$79.99 and then to $39.99 with this $40 Mail-in Rebate at Tiger Direct. Shipping adds around $9. With the savings from the rebate added, this is the best price we could find for this 600 amp emergency battery by $44. It has a 260 PSI air compressor, 1 USB power outlet for charging devices, and a built-in worklight. There is no sales tax (except FL, IL, NC, TX, GA, SD and ID).