It works better if you have the whole line, of course. It's a 5-step plan: cleanser, the pads, serum, day/night cream and sunscreen. There is also a mask called Booster, and a neck and an eye cream, but these are extras (not part of the 5-step plan). I love this line, because it's quick, quickly absorbed and it works!
Saks 5th Avenue sells it, as well. I would look at their website and compare prices. EBay's prices are usually better, but you have to do your research to find the best sellers.