A family friend is a contractor and has done work on my house. He charges me full price for his work without any type of discount. This is all fine, however when he visits my store, I’m not prone to give him a discount. I feel that since he has not given me a discount, I will not give him a discount as well. Is this under the category of not taking revenge?
Discounts are given to people with whom you have a “special relationship.” If the relationship was harmed by his not giving you a discount, your not giving him a discount would not be considered taking revenge. It simply means that the relationship is not such that warrants a discount.
However, if you don’t give him a discount out of bearing a grudge against him–ill-feeling on account of the fact that he didn’t give you a discount–then it would be a problem of lo tikom.
Perhaps he was unable to give you a discount because of financial difficulties. Or perhaps his general policy, unlike yours, is not to give discounts to anybody.
If you have true ill-feelings about it, and you are unable to overcome them, perhaps have it out with him, obviously in a well-spirited way. However, if you can overcome the ill-feelings, this is the true intent of the Torah, as the verse concludes: “And you shall love your fellow as yourself.”