The Finnish defense budget for 2022 was €5.1bn, but I am sure they bumped it up after the Russian invasion. The overall cost of the F-35 acquisition is €8.378bn (jet fighter cost being €4.703bn of that). Naturally, such acqusitions are done gradually (e.g. over a few years).

Source: https://valtioneuvosto.fi/en/-/the-lockheed-martin-f-35a-lig...