And you're making an assumption based on what your local dealers do. Things are different all over the country (and world). OP claims toknow about the guy, says he's open on Sundays. That's the verification for my assumption. I think my assumption that he may have been open (and possibly doing business) is a pretty good one seeing that the OP said... Other than that, I agree completely with the rest of your comments.
It most certainly is rude. Some people who deal with hobby items become elitists once they acquire a certain level of knowledge. They begin to look down on people and talk down to them over simple issues like terms and trivial info. It's crazy that anybody would speak that way to a potential customer. The OP will continue to call them pennies, and simply buy them some place else. It's not good business to insult people and act like a snob.