As for hidan - yes. But that depends on a ninja and on an event- sometimes you can get for free 30frags of someone (last week sailor sakura during mission dealer), sometimes 1 (this week 9tails naruto during time limited). Pretty much each ninja has its own cost and availability which transit in different ammount of time required to get them. If you have someone particular in mind, maybe we can help estimate cost and/or time needed.