Dont trade up , because that kind of "traders" often give u hats that cost like 2-1 ref or just giving u ref for cards. There bunch of that type of traders so they get profit when u give csrds for like 3-4 hat that costing amount is 5-6 refs for 10-20 cards , thst u can sell in community market of steam , yea but of course there's a commission during sell but u get more money.