F2p players should be able to play and enjoy the features and competition, but if they want a little a extra, spend some money. However, the prices should not be astronomical because then people leave and the only people who stay are the ones who can spend $5,000 in a week. The f2p players get discouraged by the increasing gap between p2w and f2p and eventually stop playing. With no people, p2w have a handful of opponents and that slowly kills a MMO because the competition and large playerbase is the whole point of a MMO.
If the prices were reasonable and most players could obtain them, the competition would never stop because everyone would keep pushing each other toward the next level. And the best part, f2p players could keep up with everyone, and in the longrun, equals more money. Simple and elegant. However, Naruto would be very upset with how this is playing out. That is not his Ninja way.