I've accumulated this sum of bitcoin through a variety of sources. I haven't bought a single one. Theoretically, isn't this income something that should be declared? I'm talking about the whole amount of coins.
I think they should be declared, even though that is often a debatable subject.
What you will pay comes down to the national policy.
In Romania I can just say it was earned through trading and will be taxed 10% capital gains tax and depending on the amount another 200-600 EURO on top for some other taxes. Not the same as income tax. Income tax is about 45% in Romania so it better not be
))If in Greece it's 15% than I don't see any reason for you to pay much more than that.
Banks are another touchy subject. Most de require proof of funds, some block accounts etc. Can't give you much advice on that front I'm afraid.
To be fair I am lucky because I know and trust a guy I call when I need to buy some FIAT with crypto. Mainly does P2P trading for a living and his services were/are used by many people I know. So would trust him even with bigger amounts, even if my average is a few hundred euros once in a full moon...
You gotta get a guy ! It's hard, he may not live close... but is worth it in the long run.
Also changing your financial residency at some point may be worth looking into but consult a professional for more info.