Don't take'em myself, for the same reasons you cite. I personally think you'll get what you need from a balanced diet with plenty of unprocessed foods. One way to find out if they make a difference, is to go off them for a few months and see if you feel any different, or if your weight changes. If not, then save that $240/year.

I know that some vitamins are required in very small amounts, and the body can even recycle them. This is why vegetarians can get away for years or even decades without biotin (?) supplements.