Walmart offers the Summer Infant Deluxe Folding Booster Seat for $13.76. (Amazon has it for the same with free shipping for Prime members.) Opt for in-store pickup to dodge the $5.99 shipping charge. That's $2 under our mention from last month and the lowest price we could find now $4. It features adjustable height and tray position, and has a 3-point restraint system.