Beckett mentioned once that they had a deal with Melo in his rookie year to purchase Game used Jerseys from him. I remember seeing an auction from beckett for a game used autographed jersey authenticated by the Denver Nuggets signed by Melo.
Im guessing Beckett did something similar with Kobe or bought a GU jersey from him directly.
Beckett also did something similar with Jordan and Tiger woods where they offered cards graded with a piece of GU material in them.