I'm up in the air ..I've never used CPs, I just turned 50, skin's sagging (I'm a smoker) and I need to do something quick for my self-esteem. Skin's sort of on the dry side; I use Retin-A nightly. I take RA really well, no bad side effects besides some flakiness. Should I stay away from the CP Serum due to my dryness and do the P & R with High Ret, or get the basic P & R? Who's got some experience with this that can tell me? Alternately, should I get the sample pack, and if so, how long would those small samples last? For that matter, how long would the 4 oz of the serum or P & R last? Thanks!