I wish Andorra, Liechtenstein, San Marino, jersey, Gibraltar, monaco would do such thing and accept all ICAO licenses (mechanics and pilots).
The pity of the isle of man is that they don't accept small aircraft, and it would have to be at least a king-air size aircraft. I think it will also be more than a thousand euros a year!
Still for me only FAA works out.
N-Registration cost 5 usd!
Trust 200 euro/ year.
Insurance 560 euro/ year.
FAA doesn't charge you like the EU. How much does is cost anyway to register nowadays in Europe? Surely it's more that 5 euros.