GameFly takes up to 50% off a selection of used games and movies, during its Pre-Played Blowout. (Prices are as marked.) Plus, all orders bag free shipping. A couple best bets, each with comparisons against buying new:
GameFly offers used Star Wars: Battlefront for PlayStation 4 or Xbox One for $14.99 with free shipping. That's $2 under our mention from last month and the lowest total price we've seen. (It's also $12 below the best price we could find for a new game.)
Walmart offers the used Minecraft for Xbox 360 for $6.88. Opt for in-store pickup to avoid the $4.97 shipping charge. That's $10 under the lowest price we could find for a new physical copy elsewhere and the best price we've seen for this game.