So the seller just happened to have a batch of items (several times!) that several buyers wanted, all for sale to each at the same time...Yeah, right
Some eBay members have what is called an eBay Store. I was looking to buy a mustang IFS from a guy in Oregon or Washington (can't remember), he had as many as you wanted to buy. My wife buys numerous Tori Amos items from the same sellers. I think her last purchase was something like 23 items from the same seller (beads, not Tori stuff). She received 23 positive feedback, but it only counted as 1 feedback. Still, you never know. Maybe this seller is legitimate and maybe not.