I have been using mineral foundation for almost six years, and will never use anything else. I have several skin issues, and have never found another method of foundation that provides so much coverage without looking and feeling like a mask.
Prices vary by brand, but of course I'm going to tell you that Beautiful Diva is the best choice.

Loose foundation retails for $19.50. but Reps get a 50% discount so my foundation is now costing me less than $10.