Walmart offers the Lifetime In-Ground Basketball System for $299 with free shipping. (Amazon charges the same.) That's the lowest total price we could find by $91. It features a shatterproof backboard, a rim built for "aggressive play" with an arena-style wraparound brace and double-compression springs, and height adjustment from 7-1/2 to 10 feet.
Need it by Christmas? Orders placed at Amazon via Prime by December 22 are guaranteed for Christmas delivery. Otherwise, place your order today, December 20, for guaranteed delivery. (Walmart charges an extra $90 for guaranteed Christmas delivery.)