Hope this is helpful!
FOUNDATION
Go cheap or splurge?: Splurge
Reason: I like to say that you should take as much precaution with your foundation as you do with your moisturizer. This is the one makeup product that goes all over your face, so you should want it to have quality ingredients. Foundations with a lower price point often have cheaper filler ingredients like mineral oil and talc that just aren't the healthiest ingredients to slather on your face daily. Another advantage to higher priced foundations is that they often have better undertones and color selection than cheaper ones.
Recommendations: My very favorite liquid foundations are Tarte ReCreate Foundation because it's free of parabens, talc, fragrance, among many unnecessary fillers, and Smashbox Studio Skin Foundation because it's long wearing and high coverage but still very natural looking.
Exceptions: If you must go cheap, try NYX HD Studio Foundation or Covergirl Natureluxe Silk Foundation. Both of these are under $15, come in natural looking tones, are less watery than other cheap foundations, and have fairly healthy ingredient lists considering their price.
FACE PRIMER
Go cheap or splurge?: Go cheap
Reason: I find that all primers, cheap and expensive, have many ingredients in common. Usually their most important ingredients are silicones that smooth the skin and help mattify through the day. Not to say that pricey primers aren't worth their pricetag; many have great added ingredients that have extra benefits for the skin. But if you're looking to go simple, there are many lower priced options.
Recommendations: Palladio Herbal Foundation Primer and Avon Magix Skin Perfector both preform well and look smooth without pilling off the skin.
Exceptions: You may want to splurge on a more expensive primer if you have found that silicones have a tendency to cause you breakouts. Two great options are Tarte ReCreate Silicone Free Primer and Lorac Aquaprime. Both of these primers are paraben and silicone free, great for breakout prone and sensitive skin.
CONCEALER
Go cheap or splurge?: Go cheap
Reason: There are tons of terrible cheap concealers that have zero coverage, but there are just as many that cover as well as or even better than super expensive options. Period.
Recommendations: Maybelline Dream Lumi Touch Concealer is high coverage and brightening. Maybelline Instant Age Rewind Eraser Concealer is also super high coverage. Basically, Maybelline is the way to go for concealers. Seriously.
Exceptions: If you want to cover and treat blemishes, you may benefit from a higher priced medicated concealer such as Murad Acne Treatment Concealer. For deeper complexions, Urban Decay 24/7 Concealer comes in an excellent range of skin tones.
BLUSH
Go cheap or splurge?: Go cheap
Reason: Not all cheap blushes are great; many seriously lack pigmentation. But there are enough great cheap options out there that make spending more somewhat unnecessary.
Recommendations: I adore the pigmentation and color range of NYX Powder Blush. Physicians Formula Happy Booster Blush is another great option.
Exceptions: If your skin tone is deep, you may need some darker blush options that won't look chalky on your skin. Smashbox Blush Rush comes in several deeper shades suitable for darker skin tones. If you have very oily skin, you may appreciate Tarte Amazonian Clay 12 Hour Blush (can you tell I'm a fan of Tarte products? I'm not sponsored by them, I swear!), which absorbs excess oils throughout the day that can cause blush to fade quickly.
BRONZER
Go cheap or splurge?: Splurge
Reason: You have to be careful with bronzer, as it can easily be too orange, too frosty, and just generally unflattering. Bronzers that are a bit more expensive tend to have a better balance of color and shimmer. Also, you're supposed to use bronzers with a light hand as to not over-apply, so at least it should last you a long time.
Recommendations: BareMinerals Ready Bronzer in The High Dive is perfectly tan without the disco glitter. Tarte Parke Avenue Princess Bronzer is a bit more shimmery, but still perfectly natural looking.
Exceptions: If you must go cheap, try Rimmel Natural Bronzer or Physicians Formula Cashmere Wear Bronzer. Both of these options are more natural looking than the typical drugstore options.
SETTING POWDER
Reason: Cheap setting powders are often, well, powdery looking. They're usually predominantly talc based, which can make them look ashy and chalky on the skin.
Recommendations: Makeup For Ever HD Microfinish Powder is sheer and silky. Tarte Smooth Operator Finishing Powder is paraben free and makes your makeup transfer-proof, yet doesn't show up white even on the darkest skin tones.
Exceptions: If you must go cheap, be careful not to choose a powder that will make you look dusty. E.L.F Studio HD Powder is super cheap, but surprisingly smooth. Physicians Formula Mineral Airbrushing Powder is hypoallergenic and has SPF 30.