Most teams wear 3 sets of home, 3 sets of away and 2 sets of alternate jerseys which is 6 or 8 jerseys a year since not every team has an alternate.
Most of the time those jerseys aren't even the ones used in cards.
Barry Meisel president of meigray posted this on the gameworn forums,
ITG is a completely different story from UD though, I believe a lot of their jerseys are won from various auctions and do have a lot of wear.
