There aren't many things I would go "high end" for, but one of them is foundation/concealer, because I can't find a match at the drugstore. It's much easier having an MA match me for the perfect color. Most drugstore lines don't have testers, so it's hard to tell what matches and what doesn't.
However, 95% of my makeup is not "high end." I've bought higher end products and for most things, I've found drugstore lines that are just as good (usually better). Some of the more expensive lines have unique items though, like...I can't find drugstore matches for some Urban Decay stuff. Overall, the product quality is far more important than whether it's drugstore or high end. I've found amazing eyeshadows by NYX and by MAC, but both lines have their misses as well. I can find incredibly cool Physician's Formula shadows at the dollar store and not so good mascara by Chanel. It just depends.
But yeah, in most of my FOTDs, you'll see me wearing my Wet 'n' Wild liquid liner, Maybelline mascara, NYX eyeshadow, L'Oreal bronzer, Goldie lipgloss, and Sally Hansen face powder, and it looks good! I've had MAC MAs compliment me on what I was wearing and they were pretty surprised when they found out most of it wasn't MAC.