Due to NA's unique economy, items are now being sold past the allowed selling price (999,999,999) in the market and player end up with trading multiple times since trading system also have the same dz limit. This method have higher risk of being scammed specially to the new ones.
There's also another method in which Weapon Upgrade Chip or Energy Converter are used as currency. If you have a lot of the said items then this one is good for you but if you are about to buy one in order to trade it then it might result to higher cost due to inflation.
Suggesting to increase the allowed selling price on market or the allowed dz for trade.
Feel free to drop your concerns regarding this one.