Certainly, if you use drugs like alcohol, tobacco or caffeine, if you're under a lot of stress or are sick, your requirements for some nutrients may be greater than your diet can provide. Vitamins in foods may be superior to synthetic forms because they can be better absorbed. Plus, other elements in foods may be present that are missing in the pill form. Generally, there's no difference between natural and synthetic vitamins. It's important to get this in its natural form because the body uses it more efficiently.
Different brands vary in cost.
I always recommend the cheapest brands that are as free of fillers and additives as possible. You've got me stumped. Because of the artificial coloring and hydrogenated fat in the Chee-tos, I'd probably go through the cafeteria line and try to make some decent choices. A handful of Chee-tos won't kill you. Here is my basic vitamin cocktail.