Answer:
Honesty.
We do not deceive or mislead.
We negotiate in good faith.
Explanation:
As a manager, I am responsible to follow ethical values of the contract. Because the contract sometimes cannot be modified. Moreover negotiations over a contract means win win situation for both parties.
Honesty: Since i had the estimate, which i could have shared with the other party but i did not because it would have harmed my profits so, I wasn't honest and violated this clause at first.
We do not deceive or mislead: Once again, I had an information which if shared could have changed the contract but since it was harmful to my business I didn't and I deceived the other party into believing that the contract is done fairly but later on the other party finds out about it they will go to court over this.
We negotiate in good faith: The purpose of this clause is to make sure that all parties involved want something better for everyone. No party is looking for win-lose situation. But the action I as a manager did, also violated this clause, for which the other party can sue me in the court.