Very simple reasons……..the cue hasn’t yet successfully sold and the seller is eager to sell it, the cue was already listed on Az but only received low ball offers or none at all, eBay offers a much larger viewing audience than Az for overall selling exposure and buyers generally have much higher trust in eBay because it will intercede if there’s a dispute between the buyer and seller whereas Az is strictly caveat emptor. The aforementioned makes it pretty clear why folks will utilize eBay to shop, buy and sell pool cues and related billiards paraphernalia, including cases and accessories. Lastly, Az has a more knowledgeable base of potential buyers so the seller will get questions about the cue they can’t answer because they either don’t know or maybe want to avoid answering so any potential cue flaws would become exposed and undermine the potential sale.