South Park: The Stick of Truth - Shopaholic Achievement

Achievement - Shopaholic
Complete half of the available costume sets.

You must acquire half of all pieces of equipment/costumes. Note that, for example, the Witch Hat, Witch Robes and Witch Gloves do not count as 3 toward the 103 counter; you must collect all three pieces of a single costume to count as 1 toward the 103 counter, so don't be surprised if you collect a hat, robes or gloves and don't see your counter go up by 1.