Target offers the Evenflo High Back Big Kid Amp Booster Seat in Sprocket, model no. 31911431, for $29.74 with free shipping. (Walmart charges the same via pickup; Amazon charges the same with free shipping for Prime members.) That's the lowest price we could find by $16. It can convert to a backless booster seat and features adjustable height, a removable seat pad, shoulder belt positioning strap, and elastic cup holders.