Kourtney Kardashian is paying the price for beauty!

The mother-of-three paid a pretty penny to have her skin peeled and pricked and popped on Friday and she emerged from a Beverly Hills medispa looking greasy and decidedly unglamorous ... but her facialist must know what she's doing -- Kourtney always looks amazing!

Certainly the 38-year-old is feeling the need to keep up with younger women and maintain her beauty -- she's got a 24-year-old boyfriend, Younes Bendjima, and her ex, Scott Disick, is dating 19-year-old Sofia Richie. Lemme tell you, there's NO way a woman in her late 30s can replicate the taught, smooth skin of a teenager -- and I'm not just referring to facial skin ... But then, the Lord knows that fact all too well!