This is question for the professional bakers out there or from others who have experiences.

I have, from time to time, been successful in buying hard to get flours from local bakeries. But I am wondering what the general feeling is regarding the right way to approach a bakery if you have not bought flour from them before. I always try to include in my purchase some of the bakeries products so I am not seen as just taking advantage of them,  I never ask about the price since they have to make a profit even on flour, and i usually try to ask the baker instead of a clerk (all the better to talk bread and get shown around the bakery). Any other thoughts to make this a positive experience?