Except that's not, in my opinion, what will happen.
1st off, I cannot be convinced this procedure (if it's ever a thing) will be covered by medicare/medicaid or regular insurance, because, I believe, it will be viewed as solely elective. So it will be restricted to those who pay.
And the donors will (mostly) not be altruistic people, they will be people who need the money (see plasma donation in the US for an example of this). These are predatory practices, preying on the poorest of the poor, for the most part.
A+B=C
Wealthy people will pay cash to buy their health off of the poor.
There is a lot of supply and donating blood is simple and easy. Perhaps the price will be low enough that the middle class can afford it and it would provide some supplementary income for young people.
But I thought capitalism was just the thing we need more of, if only we could get government out of the free market then all those problems will go away since the people on the bottom will become rich too!
You already know this but the free market regulates itself precisely equally as well as cancer. The only way any of it ever stops seeking exponential growth is when it dies with disastrous collateral damage.
If it's person-specific, imagine isolating some of it when you're still young, then producing copies and rejuvenating your aging self literally by your own young blood.
