Just like airlines today they talk with the owner of the aircraft to lease or buy! I think that this should happen! I should be able to go to an airlines and make him/her and offer to lease or buy and not have it auto priced! :)
Although technically autopriced, you can choose to offer them out at 10,20,30.....90 100% worth of their value...
You can anytime write an ingame-message to an aircraft owner and start negotiations!