Walmart offers the Evenflo Sureride DLX Convertible Car Seat in Windsor for $58.41. Order via in-store pickup to drop the price to $55.61. (Amazon charges the same for Prime members.) That's the lowest price we could find by $24. It features a 5-point harness and has a weight capacity of 65 lbs.

Update: The price at Walmart has dropped in-cart to $52.94.