The way you can do this is by owning the item twice, with two different skin quality's, post the one worth a lot of CSGOLounge, then when the trade is posted you put the item up for sale on the steam market place so that people can't see it in your inventory anymore. Now, when the person goes to send you a Steam offer, they see the other item you have with a different quality worth less, and if they don't hover over the item and notice that the quality of the skin is different then they might just fall for the scam.
I'm not promoting doing this. If you scam people of their items, fuck you.