Okay, first a disclaimer-I worked at Saks for over eight years so I have definitely sampled the most expensive lines out there, both skincare and makeup. That said, I will admit to being a bit of a snob, but I do also think there are products found in department store that would be more at home in Walgreen's; some lines that call themselves high end are basically drugstore makeup in prettier packaging.
There are some products that I simply would flat out refuse to use from mass market:
Eyeshadow. You simply don't get the payoff, level of pigment, wearability, or blendability you get from a line like Mercier, Trish McEvoy, Nars, or Smashbox. You want a color that gives you a lot of bang for your buck, because you don't want to load down the eye with a lot of unnecessary texture-you end up with a very unattractive, chunky look that creases very easily.
Foundation. Drugstore brands tend to have odd undertones, like orangy-pinks. no one is that color! They also have very little actual pigment, so you end up using way too much product and buying it more frequently, so are you really saving any money? I prefer products with light reflecting qualities, so your face doesn't look flat and makeup-y.
But. I love many inexpensive mascaras (No, not Great Lash. What is that mania all about?)I
adore Loreal Voluminous and Volume Shocking(this has a lash primer and the mascara has a tiny comb instead of a wand.)I also love Cover Girl LashExact and VolumeExact; those rubbery brushes are the bomb!
I have found some nice lip and brow pencils low-end; I prefer a drier consistency in those pencils to a creamy one anyway. I usually find eyeliner pencils to have too much drag and no pigment; not a big pencil fan anyway-prefer cake liners and creme liners.
I have seen some decent brushes lately by Sonia Kashuk for Target-I would definitely recommend to someone on a budget, but I will also say if you invest in higher quality, they last a lot longer because the hairs are hand tied instead of merely glued into the metal ring(that is called a ferrule, for you makeup junkies out there)That means less shedding, especially when you shampoo them.
As for anything with a shimmer-blushes, shadows, glosses, highlighters-you will find a much better sheen from most high end because the powder products are usually baked, which makes for a much more uniform shimmer throughout. The glimmery particles are also much finer, so you end up with a glow instead of a frosty look.
As for what I carry in my kit, I am all about longevity because the makeup has to last for many hours, often in humidity and direct sunlight, perspiration...I have used the foundation in a workout video and it worked beautifully.When you need a look to last all day long you simply have to use super high quality products.If you use things with a low percentage of pigment, you have to apply too much and you're having to touch up every couple of hours.
That is why I have so much invested-obviously if I used cheap products I would have lower overhead and keep more of my products,but what good is a pretty face on a bride that only lasts an hour?
Off my soapbox; tell me your fave cheap and expensive products?