I am on a constant quest to find a great foundation primer. When I worked for Laura Mercier (who was the first makeup artist to recognize that a primer was essential) Laura trained us to be quite liberal in the amount of product we used, and I unfortunately have retained that habit. So I go through tubes like crazy. Laura's primer is up to about $30 or more. Smashbox is about $40.
I really liked the little spraycan thing Sally Hansen came out with but it had too much iridescence. MAC's primer has the most bizarre consistency and stuff tends to slide around on it; the opposite of what a primer ought to do. Mak factor has a smashbox knockoff but it's actually quite pricey for such a teensy tube. I did the whole Monistat trick too but it feels a little unglamorous to use a "chafing cream" on your face.
Then I saw the ad for Avon's new Majix. They were promoting it a 8 bucks a pop. It is fabulous. It has the buttery slip of Smashbox, but doesn't have that weird tendency to pill up. It is not as liquidy as Laura but it really fills in pores and makes skin look smooth and evenly textured, even without foundation on top. It's like photoshop for real life. And a lttle bit goes a looong way-you can't slather it like the Laura. PLUS spf 20!!!??? Seriously buy this now, before Avon jacks the price up to 30 bucks.