I think about $20-50 on the high end as I am using mineral makeup. Its really inexpensive once you get a match and you can get a lot for that amount.
Some of my favorite links"

(great value custom kits)

(prices include shipping)

(full coverage)

(refills offered)

(the blushes look great)

(birthday discounts, good for oily skin)
Have a referral code for JLynne if anyone is interested.
So far JLynne for summer but working on fall mineral foundation to find.