Haha, my best friend calls me a MAC snob all the time. It's our joke. She use to use a ton of cheap makeup, and I got her into MAC.
It's just about my only "brand" thing I care about. I don't have insanely expensive purses ($20 or more is expensive to me), or designer clothes, so MAC is my "brand thing."
I'm a photographer, and I've had models over for photo shoots, and they see my makeup and give me lots of positive comments. Generally, they seem to appreciate someone that knows makeup and knows GOOD makeup, because face it... most cheap makeup will not photograph well! I've gotten pretty good at telling which models have cheap vs. higher end makeup on their faces.