Someone once posed the following question to Rav Chaim zatzal regarding barbers. It is the custom when one enters a barber shop to wait in line based upon when you entered. However, some people prefer to wait for the particular barber that they prefer. Essentially, a second (or even third) line forms in that barber shop.
Is this a problem of ben adam l’chaveiro? Should there be a concern that the barber with no line is being insulted in that people are not going to him? In essence, he is saying, “I do not trust you to do a good job and prefer your friend.” Isn’t this an insult?
Rav Chaim responded that there is no concern and it is no insult. Every person purchases what he wishes to purchase from whom he wishes to purchase. This is no different. This is the method of business and it is no different than a market place.
Lachazos p. 21