I'm just worried that most of the ones selling on eBay (if they're all truly selling, who knows) we will likely never see again. They fall into a void.
Those are the ones that come back around actually. The uneducated are buying commons off eBay at whatever price they can, because a) availability and b) they assume that's what they're worth (BECAUSE HOLY ****, CLACKS!), and turn around and try and trade them for rarer caps. Once they find out from more experienced traders that their 3D is, in-fact, not worth a rare bi-color clack/the $300 they paid for it, they wind up selling on r/mechmarket shortly thereafter (at a mark-up, of course, to another uneducated buyer) because it's quick money.
This is all happening right now while Clack is effectively "out" of the scene, which might be propping up prices somewhat over the concerns that he won't produce anymore (obviously he just ran two sales though). But the artisan collecting community is still growing pretty rapidly, so regardless- same supply + growing demand = increasing prices.
The Clacks that fall into the void are the private trades with collectors. They'll never publicly let on that a trade occurred (through pics or whatever), and the person that traded with them won't identify them, so they're effectively gone.