personally i think moisturiser does work. but its more prevention than cure. it won't make wrinkles go away, but it can help stop them appearing so soon, or so many.
it also helps with texture, radiance etc, but you don't need to spend a fortune, you just need to find the right one for you. i don't think i have still but i'm close!
a lot of it is in the genes though, and even more is environment. if you work outside or in a dirty environment your skin won't be as good for as long. if you worship the sun that is even worse, and smoking is even worse.