I'm actually going to work this out. Each year I purchase new foundation, power, mascara, eyeliner and lipgloss. I tend to keep eyeshadows and blushes for a few years. They're all fairly 'low end' brands, but I find that they're good quality & work well for me.
Yearly make-up:
Almay Foundation - $35.95 AU
Almay Power - $28.95 AU
Covergirl Liquiline Blast Eyeliner - $14.95 AU
Covergirl Lashblast Mascara - $17.95 AU
Loreal Glam Shine 6hr Lipgloss - $26.45
I also always buy pawpaw ointment for my lips, which costs about $5. I have a few too many lipglosses because my lips get so chapped and cracked. I'm trying not to buy any more, because I have so many and pawpaw ointment works wonders!
About twice yearly I buy facial products:
Natio Oil Free Moisturiser - $9.95 AU
Natio Oil Control Toning Lotion - $9.95 AU
Natio Wash It Off Cleanser - $9.95 AU
St Ives Apricot Scrub - $9.95 AU
Earth & Body Clear Henna Wax - $5.95 AU
My total for the year is: $220.75 AU
If I divide that by 12, a rough monthly amount is: $18.40 AU
I am looking for a good hydrating mask and an easy to apply liquid eyeliner... Hopefully I won't spend lots of money on a lot of duds before finding some good products. I always use up my products before purchasing something new, unless they're a really good sale (or I need lipgloss because I've forgotten some at home and my lips hurt... This has happened so many times!).
I guess I'm fairly low maintenance - I only wear full make-up when at work and going out at night. When I'm at home I don't wear make-up and when I'm at University I only wear eye-makeup and lipgloss. I might be high maintenance when it comes to a skin routine though! I cleanse, tone & moisturise every day, and exfoliate 2-3 times a week.