Earlier quoted context omitted.
They look pretty easily available to me, or are you going to exclude Ebay now as well? https://www.ebay.com/itm/305342386279 (note: I don't know the seller)
Yes, I'd exclude anything on the secondhand market, especially things you have to buy from overseas sellers where there's no possibility of support or returns. This is not like a normal new part where you can purchase it firsthand and expect it to perform as advertised or else get a refund. Furthermore, the (Intel) chipsets on motherboards sold to consumers don't normally support ECC either, so it seems you'd have to…
Maybe the problems you were having with sourcing the cpus you wanted have something to do with the arbitrary limitations you were working under?
Meanwhile, other people (as per sibling comment) were able to buy these same chips without issue. ;)