Board Thread:Questions and Answers/@comment-203.45.201.119-20150712060711/@comment-26518423-20150712163705

No, but I read that they don't take up storage space.

Rewards are needed to complete Contracts and Achievements. The game used to allow you to buy back items, but it was too cumbersome. Instead, they disabled the sell feature on these items... and they remain long after the contract is complete.