How much money will a 16 year old who smokes spend in their lifetime?

That would depend on how much you smoke; but lets assume you smoke half a pack a day. That's about 183 packs per year. (I'll stick to round numbers)

Assuming at this rate you live to the age of 76 (most smokers don't) That's 60 years of smoking 183 packs a year that comes to 10,980 packs of cigarettes.

The amount of money you pay will vary depending on the brand you smoke, and what he prices are in your area. Around here a pack of cigarettes varies from 6 to 12 dollars, depending on the brand and where you buy them; so lets say 10 bucks a pack. That comes to $109,800 assuming that the price of cigarettes stays the same for the entire time, as a rule however cigarette prices have consistently risen over time.