I had a very bad experience with a scammer, looking at his feedback he has a history of claiming "item not received" and "quantity less than ordered" to many sellers. In my case, I had both type of claims from him from different transactions and end up losing a lot of money.

It's safe to say he is a serial scammer. PM me if you want to know more. 

Save the tips on how to report him to ebay, I don't have the time and energy to waste on... I just want to help other sellers here.