✔ 最佳答案
Destiny, as a subscription based MMO, has virtually no resale value in the secondary markets because of the subscription fee. All the disc contains is just the game code to eliminate the need for you to download the game from the online stores.
Additionally, any DLC / codes that were included with the retail copies were one time, consumable codes... which have no resale value (as you cannot reuse them, because they're bound to your account). Therefore, there's practically NO DEMAND for it & no reason why GameStop is willing to buyback those discs.
If the game had some offline components that can be enjoyed, then there could be some interest in the secondary markets... but no offline content equates to no secondary / retail value (as it's "service only").