It's a fixed price listing.
You can pay the seller's asking price, or click "make offer" and submit what you feel is a fair price.
Only the seller sees your offer, and they can accept, decline, or counter-offer.
Sadly, I have way too much experience with the buying side of eBay!
I would not be surprised if the bidding would go up that high IF the seller was to lower the starting bid a quite a bit. Just like those new in box Bison you see every now and then. Sure they would sell for a pretty price if starting bid was lowered. My thoughts.
I do hope someone at least submits a decent offer as this would be an amazing vacuum to have in a collection.