I know NicoNicoDouga charged people to watch the Hatsune Miku concert in LA when it was streamed. I guess it depends on the act, really. The ticket price was 1800yen (tickets were 20USD when they were available) and I'm pretty sure there are other acts that do this as well, but it's way easier to get people to watch if a concert is free hence why a lot of acts end up doing free concerts instead.
Yellow Fried Chicken also appears to have charged for online streaming of a concert on NND (3000yen).
http://event.nicovideo.jp/ <-- two concerts that are set to happen that are 1000 and 1500yen respectively on NND, though you can watch a bit of it for free like how they handled CDL last year.