Warning: Spoiler! (Click to show)
I was hesitant but I decided I'd go through with the sale. The next day (yesterday), they sent a message asking what size the shoes were (again, shady). The listing clearly listed an American size along with an exact insole length. I sent a message saying please check the listing and compare it to your own shoes and I asked them to let me know that they're correct as I won't send them until I hear from them.
This morning, I got a message that asked when I was going to ship their shoes. I decided against it, called eBay and checked with them. They told me to refund their money, cancel the order and then block the buyer.
I sent a polite message to them explaining that I would not be completing the transaction. Their response?
I am going to sue you for discrimination. I sent you an address in Germany, why aren't you honest?
Looks like I dodged a crazy bullet.