Last year, I sold a very expensive item through Ebay. I had bought a robot arm off Kickstarter and ended up never using it. So it was brand new, except one of three boxes had been open. I ended up listing it on Ebay, and slowly reduced the price until someone showed interest. I had paid $2000 for the robot arm, but ended up selling it for $1500, which also included $100 of shipping, plus Ebay's $200 cut, so all told I made about $1200.
I shipped it. A few weeks later I heard back from the buyer that some components were broken, others were missing. I told him it wasn't broken when I sent it, so he should contact Fedex to place a claim. In addition the missing component was part of the unopen box, so he should contact the manufacturer. A long argument ensued, and for a few reasons I started suspecting a scam. Regardless, he asked for a refund, and I denied it, so he opened a dispute with Ebay. Ebay immediately asked me to reimburse the item and send him a return shipping label, which I also again denied, sending them all the evidence I had linking this case to potential scam.
It all went silent for months. Never once did they reach out to me asking for clarification. Then, 9 months after the sale, I got an email telling me they would debit my account for the full amount. While I had received €1051, they debited my account for €1286 (I sold the item in the US but my account is in euro). So not only did they refund the buyer without asking them to send back the item, they also took more money than I originally made.
I made many attempts to reach their customer service to get this solved. I did reach it, but "there was nothing they could do". The one time I magically made it through to someone on the dispute team I was told that they had never seen so many escalations on a case. I was hopeful, but the next day I received another email saying they were maintaining the decision. They recommended I speak with the buyer to get the product back. I told them that 1) I couldn't access my account (they recommended I just open another one) and 2) the buyer had sold the item according to his reviews (for $15, when he bought it for $1500).
All it all, this was my first time selling after being a buyer for 15 years, and I wouldn't recommend it to anyone. Their processes are obscure and unfair. No wonder the company is slowly sinking.