The competitive aspects of the game are balanced by the limited forum visits. Giving additional forum visits, no matter how much they charged for them, gives an unfair advantage in the competition to those who have money to spend. Unless you can come up with a plan to avoid that, I don’t think they’d want to do that.

The only way I see to make that work would be to allow you to have more forum visits, but have those which you purchased as extras not count for anything — no extra cred, no extra flez, no rewards, no counting in competition. Basically, playing them just for fun, without giving you an advantage in any way. Consumables consumed and item decay would need to be addressed in such a system. But is that really what you want?