The major problem with selling beads and other artifacts legally recovered from archaeological sites by archaeologists or other trained individuals pretty much worldwide is that it is against archaeology's ethics principles to sell, buy, trade, or barter items from archaeological contexts. Archaeologists are also prohibited from assigning commercial value to artifacts except in circumstances where valuation is required for the purposes of appraisal and insurance or when valuation is used to discourage site vandalism.

I know it sounds silly if a site has yielded 500,000 near-identical beads that none can be sold to help fund digs and museums and satisfy collector's cravings. But that just isn't permitted. Many years ago a small museum in the UK neatly packaged and sold some of the large hoard of identical brass nails from a Roman site to do exactly that but that is now definitely frowned on. Anal retention? No, just our attempt to keep the trade in archaeological materials at a minimum and also preserve a collection's integrity.