to bargain

• 已有定价，不须事先讲价。

  The price is fixed, so there's no need to bargain.

• 他们讲价讲了整整一天。

  They spent a whole day bargaining over the price.

• 不必讲价，反正你得把事情承担下来。

  There's no need to bargain, but you must take on the whole thing.