The Economy is a bit more complex than a few monthly tiered events. I, as a Economy Student, know this well enough
Publishing games isn't free nor cheap, so obviously Aeria has to make money from it to pay for licencing fees and whatsoever.
While I might not participate in any, I do hope they'll have some sort of tiered events. The only thing that matters is the Items you can buy in those Events, that is probably what filip981 meant.
Items offered for real money shouldn't be cash exclusive, like Slotted Helmets in Shaiya used to be, eventually certain non-gamebreaking items such as cosmetics, mounts, dyes and so on.