The point is that especially with smaller nations, it's very easy for a very small group of players to buy-contract the ENTIRE oak production in the region available to that nation. Oak already is from my experience a rather rare type of wood, so how many ports are available to Sweden with oak? More than 5? If the numbers they produce are this small, assuming 360, that's a mere 1800 oak you need to buy per day you have to buy out. That's just 270k if you pay 150per, and now you have a monopoly on supply. That's already an outrageous price, but with a monopoly you can dictate the price it's then resold at.
You want to advocate talking? To whom? We have no idea who holds these contracts.
The only thing you can do right now is intercept contraband traders leaving oak ports and hope to get lucky on their cargo. And it's fairly weird that I think "jackpot" when I read 60 oak logs, but go meh when it's 100 gold ore.