It's for real, but not good odds
Highest/lowest unique bid "auctions" have been going around for years. Mobile phone
operators love them. (Frequently advertised in supermarket counter magazines as "Win a fridge for $1.89. Last week's winner only paid $1.89 for this fridge valued at $2000). Text your bid to ..... Premium SMS rates apply")
In this case, they will charge you a small fee like $1-2 for each bid you make. Make a bid of 567.89 and you will get a message back saying that either it is not unique or it is not the highest unique bid and inviting you to make another bid (for $1-2).
Occasionally, you will get a message saying that your bid is unique, maybe the highest unique bid. A while later, you will get another message saying that your bid is no longer unique and inviting you to bid again (for another @1-2).
Eventually, it will probably sell for a couple of hundred bucks or so, but they will have raised many hundreds of thousands in "bidder fees".
The odds against you winning with just a few bids are astronomical.
(I know because I've set them up for SMS premium rate content providers and seen the numbers)