We advise you to regularly consult the different selling prices of a memorabilia, those set by players who also own your memorabilia.
To access it, you must click on “Buy from €x” at the bottom of the horse file. The memorabilia units for sale are indicated with their price, the number of units and the nickname of the selling user. If you have this memorabilia, your nickname is visible in this list and this allows you to see players who sell less or more expensively than you.
This screen allows you to adapt your strategy. In fact, at any time, you can modify your resale price by clicking on the icon to the right of the unit you own.
If you want to sell your memorabilia faster, lower your resale price. If you adjust it to the lowest price, it will be sold first whenever a user wants to buy it.
If you want to keep it longer without risking selling it, it's the opposite, adjust your selling price upwards, because the most expensive units will be sold last.