I recently sold a necklace on ebay for well over $500.00 yet it did not have to go through the authenticity rigmarole. Neither did an 18K signed pendant have to go through that process. Why some yes and others no?

Authenticity Guarantee on Signed Necklace for Listed and Sold for $2,500.00 | Ask a Mentor

Authenticity Guarantee on Signed Necklace for Listed and Sold for $2,500.00 | Ask a Mentor | eBay Community