I have not found a lot of options for bits, toolstoday.com has the 1/32 option mentioned above, but few others offer the 1/50. You can purchase them through Woodcraft, but those are shipped from Oliver so you might as well go direct. Bob had some luck buying from Canada, but he had to purchase a metric collet to go along with them and the delivery is normally a little longer since you have to deal with customs. Their prices are less though. What kills me with Woodcraft is what they charge for shipping, it's like $8 plus. Postage on something like this is less than two bucks, I don't think the envelope costs $6 so this must be a profit center too.
I haven't done a thorough internet search in a while, but if someone is importing Chinese version on the cheap I can't find them.