My kuretake brush is pretty much in its death throes, and while it's just about working now, I get that ominous feeling of impending demise everytime I use it. Wouldn't be such a bother if they were cheap or readily accessable, but nay. They ain't.
If I knew someone in Japan who could send me a box of them, as they are allegedly much cheaper and in higher quantities in Nippon, then I would be well chuffed. But I don't. Bah. Maybe time to use a real brush? Become a man?