I know most of the time that occurs when they are clueless about other designers, but still...don't they know that there are bags that cost MUCH more than Coach? That are more high end than Coach? Do they not read fashion magazines at ALL?
But, I might have said something like, "oh, I like coach too...they are so reasonably priced, but I totally splurged on this bag, but I couldn't resist" in the friendliest tone.