I'm in dire need of a wig that would be suitable for Madame Red of Kuroshitsuji for London Expo (the 25th). I don't have much of a budget and I'm getting desperate. I wouldn't be able to fork out more than £15.

I don't know the series but you could try something from here:
http://www.coscraft.co.uk/en/category.php?id_category=16

They're based in this country and post really quickly.