Oh wow...
I tracked the watermark on the Nagi pics I posted earlier, and all I can say is that the guy who took those photos has an insane collection.
Here's two pages of photos of the Nagi cosplayer:
http://mpzerocos.exblog.jp/10256092/
http://mpzerocos.exblog.jp/10058906/
And a particularly impressive Taiga cosplay I also found:
http://mpzerocos.exblog.jp/10323220/#10323220_1
I'm going to stop there for now because most of the site is around the same level and I don't want to turn this into a link-fest.