I completely understand you logic. Trading multiple cards for one does come back to bite you in the ass. As someone is not only gaining more cards, you are losing out, statistically.
I've personally traded multiple cards for 1 a couple of times. I didn't have to but for me personally the trades were worth it. Sure, it sucks being down about 5 cards now than I should be, but I've completed my priority sets. I want a lot more sets but I don't feel like I need to rush or horde cards to complete them. I can kind of chill now. Until Apink cards are here, then they'll become an instant priority.
I'll probably only trade 1-1 from now on though.
