A few months ago I bought "The Skin Type Solution"(book). The author recommended a few serums. I haven't purchased a serum yet mostly due to the price tag. I wanted to get some feedback, good and bad, from those of you who have tried these products and which is the best. Clarins Skin Beauty Repair Concentrate Elizabeth Arden Overnight Success-Skin Renewal Serum Joey New York Calm and Correct Serum La Roche-Posay Toleriane Facial Fluid Nars Brighting Serum TIA!