What is the best (and cheapest) skincare regimen out there?

I've been using Proactiv for awhile now and it works really well, but it's getting a little pricey. I want to switch over to something else. I've already tried Acne Free and that gave me some massive skin irritation, and I tried Neutrogena WAVE, which made a difference in my skin, but it didnt help the acne that was already present. I also tried the pink grapefruit cleanser which only made my face break out in a horrible rash. I was thinking I should try Clean & Clear or Oxy Clinical or someother product. Your input is much needed. THANKS!!