The Finnair upgrade cost varies depending on the route, seat availability, and original ticket class. Upgrades to Business Class can be purchased directly, using Finnair Plus points, or through Finnair’s "Upgrade with an offer" bidding system. On average, upgrade prices can range from €100 to over €500 for long-haul flights. Exact pricing is shown during the booking or bidding process... https://airlines-updates.com/blog/finnair-upgrade/