[eru]

> Under such circumstances, anything preventing a successful conclusion to the negotiations is harmful to both parties, since there exists a price at which both sides would be satisfied that they're getting more value than they're giving.

I am afraid, reality is more complicated than that. There are opportunity costs, and there are threats. (Read up about the latter in "The Strategy of Conflict".)

Threatening to do both parties damage, can give you a better deal.