You can leave most countries without realising the capital gain, even if you've built it up within a country. This is why certain people move to a country without capital gains tax to sell their company. Obviously I don't know Finnish tax law, but within the EU it's generally the case (for now). Have it checked by a _GOOD_ tax lawyer, if that's what you want to do.
Building up capital is important - once you have it there's a lot you can do.