My friend wanted some computer components and I said I would help him find them. He wanted those components to be second hand because new would cost him double. I found the sellers  and  made deals and got him his stuff and To make a little profit I increased the price a little bit to my friend. I told him beforehand that I will help with any occuring problems. I made a nice little profit , seller got his money and he got his thing in the pricerange he wanted. (He told me his price range I did not ask for more than that).  I helped get his computer set up free of cost and that was it. Then few days later he found about the side money I made and he got mad and made a scene. I tried to tell him I got him the exact prices he expected . Then he tells me he feels being scammed. I told him to go to hell.
Am I the asshole here?