Is buying CS skins worth it?

The skins do look quite cool. I was in the same boat as you, I didn't understand it then I started to play more and bought a couple of skins and now I love it. There's just something about owning a cool skin, makes you feel better in-game and therefore play better (at least for me). Not only that, you can make profit out of it. If you buy a skin cheap, sometimes they go up. I'd say it's pretty worth it.