Royals Authentic's gets balls quite often that Moylan has pitched. Reach out to them at Royalsauthentics@royals.com balls start at $35 and go up from there. Here are a couple they had a week ago:

JB 445149 9/15/16 OAK @ KC Batter:Alonzo Pitcher:Moylan Top of 4 Foul tip $35
JB 445219 9/16/16 CWS @ KC Batter:Frazier Pitcher:Moylan Top of 9 Foul tip $35
JB 880042 4/14/17 LAA @ KC B:Y.Escobar P:Moylan Foul Top of 8 $35


They also have a 2017 Spring Training GU nameplate (JC394919) available for $30.