It is useless make a counter offer.

讨价还价是没有用的。

Our counter offer is in line with the international market.

我方的还盘与国际行情是一致的。

Our counter offer is in line with the international market.

我方的还盘与国际市场行情是一致的。

This price is already too low. We really can't accept your counter offer.

这个价格已经是很低了，你们的还盘我们实在没办法接受。

A counter offer should be handled with great care and with an eye to good will and future business.

对于还盘的处理应该非常谨慎，必须着眼于良好的意愿及未来的交易。