He hadn't 'bargained on' how his new position in the company would change the way people treated him. [=he was surprised by how his new position changed the way people treated him]
You're allowed to go to the football game tonight, but I expect you to 'keep your side of the bargain' [=do what you agreed to do] and clean your room.
They've agreed to turn the land over to the state, and the state, as its part of the 'bargain', has agreed to keep it undeveloped.
(..) Oh, they're darling. What are they? Thimbles? Yes, and they're quite old. lt's full of saffron. Just in csse you think l'm going to give it to you to encourage your sewing. l don't care to bargain. That day, did you follow me to the market? Yes, of course. Shall we be all right? Yes. Yes. (..)1996 The English Patient
(..) You've been cheated. Oh, don't worry, we'll take it back. l don't want to take it back. - This is not worth pounds. - lt is to me. - Did you bargain? - l don't care to bargain. That insults them. l don't believe that. l think that you're insulted by me somehow. l'd be very happy to obtain the (..)1996 The English Patient