Trading and selling photocards of Kpop idols is part of being a Kpop fan. Preordering your fav’s albums, group orders, special editions, lucky draws - that all requires time and money. Sometimes a lot of money. It is only natural that if you buy multiple copies of the same album and end up with duplicate photo cards, you would want to trade or sell extras. (Myself included!) Who doesn’t want to recover at least some of the money spent.