My favorite foundation isn't cheap, but I have found that Revlon Colorstay is a cheaper alternative that I like almost as much. If the color matches you this is my top drugstore foundation pick.
e.l.f cosmetics is the cheapest makeup you can find and some of the products are surprisingly good. The makeup brushes are pretty good starting at $1. My favorite product of theirs is the waterproof eyeliner pen $1. I like each color! It is like a felt tip marker and it stays on my eyes all day without flaking. Pretty remarkable for $1. They also have a good $3 eye primer, it is mineral eyeshadow primer. I have used it and recommend it if you don't want to spend $18 on a better one. Their $1 tweezers are remarkable. They work almost as well as my tweezerman. They are great for eyebrows, but also for your first aid kit. For $6 you can get their studio high definition powder which is almost as good as my $30 favorite can't live without Make up For ever HD powder from Sephora. I also like their studio makeup remover wipes $3. I have tried their eyeshadows and don't like them much. They are really small and go on light.
Place an order by 6-28 and you get 50% mineral makeup and $1.98 Shipping. Usually their shipping is $7. eyeslipsface.com
The other cheap makeup I think is totally fine to buy is cheap mascara, especially clear mascara for your brows. e.l.f has one that is gloopy, but works. I like Maybelline Great lash- clear.
Maybe someday I will convert to drugstore makeup- who am I kidding, I will always be a Sephora addict! I waited in line an hour just to get in the store the day it opened and another 45 mins to buy something, I even saw myself on the news waiting in that long line. I loved every minute of it. And I will forever be won over by pretty packaging.