They are all from the same seller (who is over 1500 feedback), I imagine he is just trying his luck with the three listings, and if it sells at a buy it now in the next few days, he will cancel the auction.
IIRC it's against eBay policy to have multiple listings for the same item.
It seems you are correct, from eBay:
"To ensure buyers see a wide variety of options from a variety of sellers, we don't allow more than one fixed price listing of an identical item at the same time, from the same seller.
You can have more than one auction-style listing for identical items if you don't add Buy It Now, but only one duplicate auction-style listing without bids will be visible to buyers at a time. Once the first listing receives a bid or ends, the next listing will appear on the site." (from here:https://www.ebay.com/help/policies/listing-policies/duplicate-listings-policy?id=4255)
So I think you can have 1 fixed price and 1 auction, but not 2 with a fixed price.