Earlier quoted context omitted.
I've had two disputes that materially ignored the facts of the dispute, in one case where even the buyer said he didn't and wouldn't do as agreed, and still won, costing me $700+. You can't say "I've had a few disputes that were handled fairly, so when other people say there's weren't, that's not the standard eBay experience".
I've sold on eBay for over 20 years and millions of dollars. I would like to know more about your experience as a seller where you had disputes handled poorly, especially one that cost you $700?
Then, three weeks later:
"The batteries don't work. I want a refund."
"Batteries? Any of them? All of them?"
"All of them, none work. I want a refund."
Note that two of the batteries were less than 4 months old, still in warranty.
He then stated he wanted a refund of $800. For five brand-new batteries, that would only be $670.
No evidence was shown, despite multiple requests (like a video of a battery on a charger, or on the drone, failing to power up). I stated I'd like to get the original batteries back, as at least I'd be able to get them replaced under warranty or possibly repaired and recoup some of my money (I was skeptical there was -any- issue, but still, good faith). He "happily" agreed. I asked him to send me a message on eBay (so it was tracked and not avoiding their system) acknowledging that offering a partial refund was contingent on his sending me the batteries back and that he accepts me disputing the refund if not.
He sends a message indicating all of the above.
Refund is sent (for about $700, to include his return shipping costs).
Thirty-five minutes later, I get a message, "USPS says they don't ship damaged batteries, so I will not be returning them". (35 minutes? So what, you were just sitting around waiting for the refund, and then the very moment I sent the money, you jumped in your car, got to the post office, had this discussion, got home, and were able to send me this message? When your home address shows you about 15 minutes from the nearest post office?)
I then suggest we meet in person to exchange them (I live a few hours away, not convenient, but still, $700...). He umms and ahhs, "How will I be able to prove that I gave them to you in person?". I suggest we do it in a police station and point out that his local PD even welcomes people to use their lobby for CL, etc. on their website. More umms and ahhs. "I need to contact eBay support to see if they allow this." I point him to eBay's specific FAQ page describing exactly this and how they recommend doing in person sales, and refunds, documentation thereof, and how they support it. But he ignores that and says, "I never heard back from eBay support, so I'm not sure what to do". I point this page out again, and he goes silent.
I opened a dispute. No evidence was provided for damage or faulty goods, referenced the multiple requests for video, or of anything.) Multiple instances of the buyer trying to show something was problematic with the listing, not abiding by the agreement and refusing/avoiding any method of returning damaged items.
Overnight, no further inquiries.
"We have closed your dispute. Based on our review, the buyer is entitled to keep the partial refund for damage. He is also not required to return the damaged items".
So he ended up with a Mavic 2 Pro, with less than 20 hours flight time, 5 batteries, for in the order of $950, all told.