I can apprecaite your sense of disappointment. I would encourage you, however, not to judge the entire shop/store based on this singular experience. As you know from other areas of your life, building a relationship means working through rough times as well as enjoying all the smooth ones. There are many reasons that could easily explain the interaction you had with this person. Yet, if the shop has been around for 90 years, they must be doing something right.

If it were me, I'd make a return trip, and attempt to talk with the same person again when the shop is not busy. I'd let him know that I was looking for a shop with which I could build a long term relationship, and was just a bit put off by our last encounter. I'd probably say something like, "I just wanted to make sure that I followed up with you, so that when we interact again you'll have a better idea of who I am as a potential long term customer."