I'd assume EQ II is going to be the same.
EQ I introduced something called Krono.

Krono is bought with real cash, on the station store.
It is an in-game item, which a character can use to purchase a month of 'Gold' subscription.

So it is a legitimate method to convert cash into game currency.
But it is also an item which, once you have platinum generation going in the game, you can pay for your subscription entirely through in-game resources instead of your wallet.

The Silver level lets you accrue 1,000 AAs, which depending on class is somewhere around 65th to 75th... before you need more than that to be average power for your level.
You can spend station cash to raise your cap by 250.
But you can also go 'Gold' for a month, to remove your cap... and then revert to Silver status and keep anything you earnt...