The problem with ebay is there are both new and used items for sale, so I'm not sure if something is used even if described as new. Also the bidding seems too complicated for me, so I only "Buy Now".
I have never had a problem. I just click "buy now" and "free shipping" and "new only"
Generally anything I'm buying comes up "over 10 available, 216 sold" or something like that. That makes it extremely unlikely that it's a used item.
I do have my first dispute in 10 years of using ebay open right now. I bought an RD32II camera from China, and it's been stuck in the post for 8 weeks. I told him I'd give him until Tuesday, which is 3 days before the last date to settle the dispute. Honestly, it's just never going to show up. I ordered another identical camera from another Chinese vendor 5 weeks after ordering the first one, and I've already been using it for over a week.