I mean, last night the wizard complained that in 4 sessions, we never found a place of power for him to use; we argued a bit, some other players joined us, then we concluded that, since they were in a forgotten underground metropolis, it would have made sense that, searching well enough, they could find a suitable place of power. However, I felt like that in this way, the players just had an easy way to prevent a couple impending dooms doing that ritual. Also they didn't seem too much worried when I said that they risked to permanently taint their own souls doing a ritual in such a fiendish place of power. I'm too much of a long time planner when comes about antagonising the heroes :P
So, to recap my question: how often do you find places of power in your games? Of what kind are your average places of power? Like, can you rent one in every major town, or are they incredibly rare places found only in the most forgotten corners of the world?