It's possible to buy/sell land in the game and i've read that all ships are individual and named units so can they be sold and bought. This happened in reality, the japanese buying old and not-so-old British ships, so did the Ottomans.
-
We have updated our Community Code of Conduct. Please read through the new rules for the forum that are an integral part of Paradox Interactive’s User Agreement.
I know you can buy land, not sure about individual ships.. but I believe Ammo, infantry weapons and artillery are "resources" in the game, which can be bought and sold ... I doubt they have any effect on the technology of your military though.
If you look Aprof´s AAR you may see that you can buy and sell cargo ships. If you can buy and sell tech and provinces as Patric showed when he tried to buy Azores then you should be able to buy and sell warships.
I'd hope that you can build/sell basic warships like Frigates or even possibly DD's in some form or other. I don't know if it should be via diplomacy or the World Market thou.
Buying warships should be via the diplomatic system, IMHO. Most countries would have a problem with 'profiteers' trying to sell modern warships to potential enemy states. 