Profit

The profit is displayed in the offer box when a customer is offering to buy an item from you, or sell an item to you. The profit is simply calculated as the difference between the price being offered and the market price. It is defined so that higher numbers are always better; that is, when a customer is buying from you, a positive profit means that the customer is offering more than the market price, while when a customer is selling to you, a positive profit means that the customer is asking less than the market price.

Note that even an item sold for less than market price can turn into profit, because market price is an arbitrary number that doesn't take into account crafting time + used resources.





(Note that prior to the October 27 update, profit was defined differently. Some research about this is preserved at Profit research.)