The Bureau of Engraving and Printing "manufactures" collectibles for direct sale to the public. Are there banks of other countries that do the same? I checked Bank of England, Bank of Canada, and a few others, but did not find any such offerings. Many mints from around the world do offer collectibles, but this does not seem to be the case with their paper (or polymer, in some cases) currency. Is anyone aware of any such collectibles from other countries?
China does, you can buy whole sets of currency, auspicious serial numbers, older notes, sheets etc. They have state owned stores that sell these. China is a remarkably numismatic friendly country to collect current stuff from.
I bought them in China. I know they sell them in Ukraine, but usually in banks and the prices are too high.