I had this same issue with a mom and pop thrift near me. They asked me why I was buying a bunch of women’s sneakers and electronics. I explained that while I collect certain items (true) I also resell (true). The pop didn’t care but the mom felt like I was ripping her off. I had a convo with her saying I would be willing to pay a little more for certain items but if she didn’t want to sell to me that was her prerogative. I also told her how I am a respected member of this community and it would not be a good look to ban me from her store. She eventually has turned into a good friend considering over the last 5 years I’ve probably spent close to $10,000 at her little shop.