How? Without sounding too flippant, it won't help them pay their taxes, buy their homes or raise their children...?
Because it will give people a great deal of predictive knowledge about themselves: mental health, personal health, your kids health, etc. And that there will be more and more knowledge available each year.
Just on the physical health side, having knowledge about how to drastically increase your physical health will allow you to plan your lives better and thus be a better parent/home owner/etc.
Heck, just finding out that you *don't* have genes associated with lung disease can change your life: never mind finding out that you *do*
I'd think it would definitely help them raise their children, at least from a medical, food, and possibly even prod into the proper field of study POV. Though, looking at that graph, even once it hits $0.01 per base pairs, at 3 billion base pairs in the average human, we're still talking only multi-millionaires being able to afford it.
Another frightful possibility is what can happen if an enemy gets your base pair. What hard to detect poison would our President be most suseptible to? Well, now our enemies will be able to figure that out if they can get their hands on our CIC's DNA.
We're currently at about 100 base pair per two pennies (the OP was wrong). Think about it for a second, your eyeballing of the graph led you to predict a 2007 price about 50x greater than it currently is. It's similar to thinking about getting a $20,000 second degree from a local University, and then finding out that the same knowledge is actually available for $400 and is just as reputable.
It's currently less than a million dollars for the whole genome (which, tbh, is a pretty good investment for anybody with more than a hundred million dollars, giving the predictive power that is coming online and the advantage of applying predictive power sooner rather than later. Additionally, metapopulation studies would be using your data as a significant sample source, meaning the data is being applied to you first.).
But you needn't get your whole genome done. We're soon going to be moving into a market where you can get 'packages' of genes sequenced. Getting your specific alleles for 'only' ~6,000 genes will be something that almost anybody can afford.
And finally, there are people that assume the line will trend downward. Note that the graph is logarithmic.
Seriously, we're on a cusp. And the average, careered adult needs to be well informed of this - else they're missing a huge opportunity. If a person has time for Prime Time TV, they have time for this. And the rewards of
knowing about genetics is much higher than
knowing who won whatever is showing on reality TV.