How about buying an overseas airline that has gone bankrupt...
I don't think they will allow the transfer of planes, since it create a great chance of abuse for players, for getting planes ahead of the building queue.
If it allows you to operate in different countries, you should better play OPEN, instead of REALISTIC, saving the trouble of modifying the game. If it doesn't allow you to operate in different countries, and doesn't allow you to have planes tranferred, what's the point of buying an overseas airline.
well, by spending allocation 5% on the top 2 method and 2% on the third already receive full marketing bonus. i spend around 500M per month, and adds 16% to the reputation