I had it happen one time buying from Canada too. It still shows “last one” on ebay, so I don’t know if you have to click the BIN button and click “commit to buy” to reserve it before it goes to someone else…
Oh I did hit BIN and when I went to pay, that is when the trouble started. I sent him a message and today
it shows up in my cart to pay but when I do, get the same message. So I took a picture of it and sent him
a new message requesting an invoice. We'll see what happens.