Sam's Club offers its members the Grape Solar 1,080-watt Off-Grid Solar Generator Kit for $2,899 with free shipping. (Non-members pay an additional $289.90, so it's better to just get a Sam's Club 1-Year Membership for $45.) That's the lowest price we could find by $600. It provides 3,240 watt hours per day, with a powerhub that includes four AC outlets. Deal ends August 17.