>It sounds as if this is a case of "previously worn" = "antique".
Personally, I doubt that. I'd bet money this is a new item he's buying in bulk.
For these really to have been previously worn (ie. 'estate'), he would have had to have found at least three *duplicate* necklaces, with the exact same mm pearls and the exact same clasp (since he's using the same pictures), all from one or multiple estates. And all within such a short period of time that he could sell them all within one month of each other. Of course, I'm not an estate dealer either, but I don't think that's normal for estates. What's more, based on his feedback from others, he would have had to have had "miraculous coincidences" like this occuring regularly. I don't think *statististics* work that way either.
There are indeed selllers on ebay who sell multiple, identical, new items, one after another so that there's never more than one listed at the same time. I'd say lots and lots of sellers, actually. Based on this seller's pearl listings, as well as comments left by others in his feedback, he does this repeatedly well. He probably actually is an estate dealer who actually does sell 'unique' estate pieces, but who also buys some newer things in bulk and sells them off one at a time. He'd be far from the first to do such a thing.
He just happens to slap the word 'antique' in front of everything, apparently regardless of whether it really is estate, or is an item he's buying new in bulk. (And in all honesty, I don't think 'antique' is even synonymous with 'estate' or 'previously worn', is it? I'd read some time ago that to upstanding estate dealers, 'antique' means at least 100 years old?)