It depends on the product and the line.
For eyeshadows for example, the higher end/trendy lines have a lot more variety of color, textures than drug store lines. Some of them also last longer/less creasing in my hands as well. I think this goes for foundation as well---esp for my skin (l'm african american) I found it impossible to find a drugstore foundation that matched my skin and didn't make me look ashy.
Lipsticks are probably about the same quality, but again variety of color is more the plus of upscale lines (I like MAC). Plus you often can use a tester and truly see a color as opposed to those plastic drugstore color samples which can be way off.
Mascara you have to change so often I think the cheap is fine---have never tried the high end ones.
Novel products (stains, convertible all over colors) usu pop up first in trendy lines and then trickle down and get knocked off so if you're into cutting edge stuff, trendy lines are good. The packaging is adorable (Stila is one of my favorites) but if the product isn't good, the packaging will not tip me to buy it.
4a with 3c patches/LOIS daughter O/S spongy fine, natural since 1999
Perfection is not attainable. But if we chase perfection, we can catch excellence.
- Vince Lombardi