贸易往来中，买家总是觉得价钱太高，卖家总是觉得自己的价钱合理、再低就亏了。在这种情况下，谈判、争论、讨价还价不可避免。
讨价还价信也是说服信的一种，这种讨价还价信的目的是使双方达成一致、做成买卖。为了更多的为己方争得利益，写信的时候一定要强调己方反对对方要求价格的原因，并要提出双方都能接受的条件。
写讨价还价信应遵循下面的原则：
1. Thank-you expression for what the reader has done.
2. State reasons for non-acceptance and inability to take the desired action.
3. Make a counteroffer or suggest that there may be other opportunities to do business together.
4. Mention the possible benefits associated with the reader's concession and encourage him to take action.
5. Close the letter courteously and positively.
下面是一封要求对方降低价格的信，我们来看看是怎么写的：
Dear Sirs
We write to thank you for your quotation of 20th March and the samples of the LTZ Trimming Edge Cutters you enclosed.
Having carefully examined the samples you mailed, we feel quite satisfied with the quality of your goods and the way in which you have handled our inquiry. It would be profitable for both sides if a long-term business relationship could be established
However, our marketing research reveals that the prices you quoted appear to be on the high side even for tools of your quality. Goods of similar quality which are sold at the prevailing levels are three percent cheaper than yours. Some of our clients feel worried that accepting such an offer would only leave them with a small margin of profit on their sales.
May we suggest that you perhaps make some allowance, say, two percent off your quoted prices? We feel confident that the revised ones would help introduce your products into our local markets. And you could also rely on large volume of orders from us if our customers see increasing benefits from their deals.
Please kindly inform us of your decision as soon as possible because we need your information to work out our import schedule by the end of this month.
Yours faithfully