I recently bought a used impulse sealer for plastic bags on ebay. It had all the features I wanted and the price was right. The condition was listed as "New", very slightly used. That's not what I received. The sealer was missing parts that were shown in the auction pics, and showed signs of very heavy, long-term use. I decided I needed to return it, the item just wasn't in the condition listed. I contacted the seller, and we talked nicely about it back and forth for a few days, and I asked him to send me a call tag and refund my auction price, plus what I paid for shipping. No response for a few days, then I received notice that he had refunded my entire auction amount. He sent me a brief message asking me to keep the sealer as an apology for it not living up to his billing.
I'm uncomfortable with that sort of thing, and I replied to him offering to pay return shipping. I was kind of feeling like a scammer somehow, even though I hadn't done anything wrong. I received no response, and after a week or so I ordered the parts necessary to bring the sealer up to the condition I originally expected. The parts totaled almost the original price of the sealer itself, but it'll work properly, and I really need one. I'm still puzzled about his decision, but it appears that he realized that the repairs exceeded the value of repairs, and did this to cut his losses.
I left him excellent feedback, but with a slight "ding" for the condition not being as advertised. I never heard from him again, and am satisfied, but a bit puzzled by the outcome. There are some decent people on ebay.