Oddly, I've found somewhat the opposite - I usually shop at a grocery store in a lower income area, not because it was cheaper but because it was more convenient. That store closed recently and I've started going to a grocery store in a more affluent area. I've had no difference in how I've been treated by employees at the store (I always try to be polite to them, it costs me nothing to say please and thank you) But the people in the more affluent store? I DREAD going to the store because of them. My other half is a bit of a punk, she has bright blue hair, multiple piercings, and visible tattoos. We constantly get glares at, have had multiple "can I speak to your manager" types make disparaging comments at us, and constantly have problems with people just being, for want of a better term, colossal pricks. One even going so far as to hit my partner with their cart and call her a "fucking bitch" to her face... If they treat us like this I feel bad for the employees of the store.

Multiple times we've debated going out of our way to go to a store where we don't have to deal with these type of people. Not to save money, just so we can be treated with some modicum of respect by other shoppers. I've never liked grocery shopping but the people in more affluent areas just make the entire experience something I dread.