The easiest way to make money (The Witcher 3: Wild Hunt)

This is perhaps the easiest way to make money in the game. First you need to go to the moneylender in Novigrad (just above the south gate). We buy all the florens from him. If you still have crowns, exit the trade mode (but do not close the dialogue) and enter it again, and so on until you spend all the crowns. After that, head to the Vivaldi bank and exchange your florens for crowns. You can repeat these steps endlessly.