There are two ideas that I like. First, allow players to purchase anima like this...

First anima purchase: 5k. Every additional purchase effectively doubles the cost. Second - 10k, Third - 20k, Fourth - 40k, Fifth - 80k, etc. The NPC can give some technical mumbo jumbo that forcing anima in the body gets progressively more difficult, hence the rising cost.

Here's the catch: 36 hours after the last purchase, the anima price drops back down to 5k.


Or, I like the idea of earning anima through a quest reward. If I was a cruel person, I'd say the quest involves delivering a sensitive package from one city to the other. Teleporting would only destroy its contents so you have to hoof it. Then I'd have aggressive mobs around your level spawn along the path, forcing you to either run around or fight your way through.