Aha - that's what this is. I keep wondering why many sub-20$ items on eBay keep getting cancelled on me. The equivalent item on Amazon is usually 20-25$ (but doesn't quality for free tier shipping on its own) so I shop eBay for same - half the time or more recently it's either a) a drop-ship from Amazon even in its box/packaging, or b) cancelled as 'buyer requested cancel'. I knew it was a scam but I didn't know what for.

Good thing I ship to a PO box and use a generic C/O name.