If you buy on eBay they are required to send items with tracking. No tracking means you can just ask for a refund and you’ll receive it automatically since they can’t provide a tracking number. The major carriers also do rate adjustments if the seller tries to underpay for packages by listing the wrong weight. Unfortunately as a seller this also means that you have to watch for erroneous weight adjustments and contest them when they crop up. I think it happens when your package is sitting on top of another package when it goes under the automated photo system.

I’ve never had an issue with receiving a package from eBay and I buy and sell on there all the time. I had one package I shipped get lost, I had another I sent through eBays international forwarding service (Pitney Bowes) who said they wouldn’t forward it because of the materials in the item. It was not listed as a prohibited item and isn’t prohibited to ship internationally, I got to keep the money and the buyer got a refund.