Summary: Using the word let’s to imply that you are both on the same team and that you are working for the mutual benefit of your counterpart.
Let’s is a powerful word when it comes to soliciting cooperation from others. Instead of saying, “You need to sharpen your pencil to see if you can come up with a better price,” you could say, “Let’s reexamine your numbers and options and see if we can come up with a better price.”
You are able to get the same point across in a much more cooperative way. The word let’s is powerful and it works better than saying you.
Let’s is a difficult word to counter without coming across uncooperative. A strategy that could work well in this situation is, If You Were in My Shoes. For example, if you had already given your counterpart a rock bottom price and going any lower would make your sale unprofitable, you might say, “I am struggling with where to go next. If you were in my shoes, how could you justify lowering the price to a point where you create an unprofitable sale?”
You may also counter effectively with the strategy of Asking an Open Ended Question. You might ask, “What specific ideas did you have in mind for me to get you a lower price and still remain profitable?”
Have you used or encountered this tactic in your negotiations? If so, how’d it go?