Turns out there's a bug where you can remove gold and items from a trade when the other player is still locked in without having it unlock for them (if you remove the item and accept the trade fast enough), allowing you to just instantly take what they have, and most of the time, not have to pay for it at all.
Just got scammed for, about 100K gold worth in Legendary Mats.
And be aware that people can just take all of your stuff without paying a single gold if you're not paying enough attention.
Edited by SirGabenOfSteamia on June 27, 2016 11:53PM And so, Akatosh revealed himself to a young Gaben, and granted him purpose.
"Grant them Steam sales," he commanded.
And obey, he did.