This first week has been fun, but yes, the prices are extremely high here. The population will not last at these prices. People will soon be hitting the brick wall in front of them.
If I had to guess, I would say that 30% of the entire Aden population will be gone within the next 2 weeks.
After the first 30 days has passed, at least 50% of the entire day 1 population be gone.
There would be a population drop no matter what, for any game. But one of the biggest problems with L2 Aden will be getting NEW players to join and help fill in those gaps. The barrier of entry for new players will get higher, and higher, as time goes on, and p2w items are introduced. New players simply won't be coming.
The current players will slowly bleed out from paying $25 per L2 8000 box, until only the most hardcore are left.
This is what happened to EU, where Siege turned into 1 party vs 1 party, and in some cases, 0 parties as the castle would be left unclaimed.