When buying and selling, you should take the market spread into account: the difference between the price at which you buy and the price at which you sell.
On average the spread is around 2.0% and depends on spot price, liquidity, volatility, and wholesale market conditions. It is a property of the physical metals market rather than a fee Eona adds on top.
Prices on the platform are based on live global market rates, and your dashboard updates in real time with current market values.