I've got some ER16 collets (a set of 11) and 7 ER16 collet nuts that I was going to discard, because the previous owner of the tooling did not understand how to properly assemble the collet into the nut. In short, the collets are kind of chewed up on the outer groove where they are supposed to click into the nut, and some of the nuts have cracks in.
But, I know there's likely a scrounger or two out there that would be willing to use this kind of "junk", especially for low accuracy work. You'd have to bore and thread your own collet receiver, though. I'm going to use the Cat40 holders after I get some new nuts for them.
So I'll pay the postage in North America, and you donate that same amount to cnczone. I'll wait until Monday for any replies here from interested parties, then pick one at random.... if there are any interested parties