Lol, i'll make it more simpler. (in my mind of course) Here, do you like summoning? Well, shards are 25 each at the store, and people sometimes buy too many and want to get rid of their shards. So, they sell to other people for 23 each. Now, you ask, how?! The trade price is 25 each, its not like they can change it. Heres how, since you want the shards, and you got so much junk that you don't need, you pay them in a mixture of money, and junk. So, if you wanted 1000 shards. You would get: 1000 shards Seller would get: 23k 2k worth of junk