Private inputs → win-win gains
We each have a private cut-off point —
the seller's true minimum and buyer's maximum for doing this deal.
We agree to run this protocol once, honestly inputting our true values.
If there's no overlap, we both walk away with no hard feelings.
If there is an overlap, the protocol will let us know, without revealing our private cut-offs points.
No retries. No need to waste either of our time if there isn't a win-win deal possible in the first place.