Yep. When I sold my last Iphone, the guy said the wifi had connection issues (It was the version where your finger could reduce the signal). I told him that that was a known problem with the phone, but if he still had problems with it, he could take it to an apple store as the phone still had applecare+. He said the apple people are mean and he didn't trust them. He kept trying to get me to compensate him $50 for a repair until finally he ended up returning. So annoying.
Another lesson about ebay: Don't ever ship something to an address other than the one ebay has. My brother sold his phone and the guy asked him to ship it to "his daughter's house for a present". Turns out the account had been hacked and now he had just sent his phone to a scammer.
The last horror story i have: The same brother sold an iphone on ebay and the guy claimed it came with the screen cracked. Ebay sided with him on the return and my brother received a letter in return with nothing in it. Fortunately for him that time, ebay just let him keep the money and the scammer keep the phone (albeit, after 2 hours of arguing with their customer service).
TLDR: I've had way too terrible experiences on ebay to ever use them again.