what are the ingridiants of the flavors?

The federal regulations on food labeling state that "[t]he term natural flavor or natural flavoring means the essential oil, oleoresin, essence or extractive, protein hydrolysate, distillate, or any product of roasting, heating or enzymolysis, which contains the flavoring constituents derived from a spice, fruit or fruit juice, vegetable or vegetable juice, edible yeast, herb, bark, bud, root, leaf or similar plant material, meat, seafood, poultry, eggs, dairy products, or fermentation products thereof, whose significant function in food is flavoring rather than nutritional. Natural flavors include the natural essence or extractives obtained from plants listed in 182.10, 182.20, 182.40, and 182.50 and part 184 of [Federal Regulations Code Title 21 Chapter 1], and the substances listed in 172.510 of this chapter."

Is this seriously $10 for 8 cans??? Its $4 for 8 cans in my local store...

Yes you are correct, however, due to differentiated shipping and costly Amazon fees there isn't much profit as it appears.

What does 3FL lime yours mean?

It means 3 Flavors in that pack. Several different packs avail with different flavors in each

What are the health benefits?

Health benefits to me are no sugar and flavored water, and the carbonation. I have given up soft drinks which are so loade with sugar and are so bad for your bones. Hope that helps you!