What? Who are they? And why will they kill you? Indeed, I found the opposite to be much more likely. If you try to prevent most of the people from obtaining it, that people will do whatever they need to obtain it, including killing you. I quote from a comment at FightAging! that better explains it:
Too many people are paranoid of the whole "rich people want to keep it for themselves" thing.
I think the arguments against that are of five separate types: the moral, the financial, the social, the practical, and the consequential.
The moral: This is probably the weakest argument, but restricting access to longevity therapies is against the morality and ideologies of everyone involved in the business. Seriously, pick a name you recognize at SENS, Calico, the Buck Institute, anywhere; I guarantee that person will be opposed to restricting longevity therapies to any subset of people. Now, it could be that a few of these people are secretly uneasy with the idea of the world's worst, most useless, people also getting it, but they aren't dumb enough to say that out loud, because the overall morality is one of global access to longevity. (Expect the same with future transhumanization, most notably intelligence improvements.)
The financial: This is probably the stickiest part. "You won't be able to afford it" is a lot more credible than "It will be kept from you". People seeking wealth want to charge a lot of money for their products, especially to effectively captive audiences, and so overpriced drugs are a real problem. However, insurance companies will be a lot more willing to either negotiate those prices down or simply pay them anyway, because fixing problems in one shot is a hell of a lot cheaper (and easier to sell!) than prolonged end-of-life (also known as slow death) care. That's for private insurance; countries with socialized medical care don't charge their citizens. Similarly, the U.S. government, facing eleven-figure debts to the elderly, will find it much, much cheaper to keep these people out of nursing homes if it can't just eliminate the "elderly" category altogether. A lot of organizations offer assistance for people who can't afford lifesaving medical care, which is what this is. And prices always, inevitably, drop at some point, just as they have for everything else.
The social: People live in monkeyspheres, which intersect with other monkeyspheres, ad infinitum. Does the security guard's crippled mom get regenerative therapy for her aged spine? (Probably yes, you don't want to piss off your security people.) Okay, now this woman has a lot of friends her age who just watched her toss aside her wheelchair. Perhaps they have wheelchairs of their own they'd like to discard. She'll be asking him when they can get it, too, and it'll filter to his boss, who likely has a lot of other people suggesting to him that their friends, or their friends' friends, should get it at an affordable price. It's difficult to quantify the weight of this pressure, the power of literally everyone you know going "Listen, my mom's gonna die if she doesn't get..." SENS already has a lot of people going "uh, so yeah, when can I get fixed?" even though there aren't even any human treatments yet. Imagine the cacophony when there are! And then there's the clinicians whose patients can't afford it but need it to keep breathing.
The practical: Competitors have a wonderful habit of popping out of the woodwork once it's proven that a thing can be done. If your prices are too high, someone else does it for cheaper. You can't keep it a secret, and it's a hell of a job to prevent everyone, everywhere, from copying your techniques. The battle between generic manufacturers and patent holders is well-known, and that's for stuff that barely even works, let alone makes fundamental parts of people younger! (And, of course, a lot of these drugs will be fake, causing news headlines and a lot more screaming.) What happens if some large country just goes "Screw your patents" and institutes a national longevity program?
The consequential: Okay. Let's say that longevity treatments were, against all odds, somehow bought out and controlled by a cabal hell-bent on keeping them from the masses, charging tremendous amounts of money, refusing to listen to social appeals, and instituting global draconian patent protection to keep anyone else, even Eurosocialist countries, China, and Russia, from copying their techniques and making them available to the general public. What happens when literally everyone in the world is dying of old age, except for a few people who aren't? What might everyone do? Riots in the street would be the go-to approach, although it probably wouldn't even get that far; any candidate who ran on a "These people are getting indefinitely rejuvenated right now, vote for me and you won't rot to death" platform would sail to victory. If the democratic process failed to the point where that wouldn't be effective (and now we are firmly in implausible nightmare world), people might do literally anything in response. It's their lives at stake! All-out corporate hacking, robbery, hostage-taking, assassinations, outright terrorism of the splodey and shooty variety, you name it. A hotel maid, whose father died of curable Parkinson's, hands a door keycard to a man whose older brother died of curable atherosclerosis, and in a few minutes that maid has a lot more to clean up. A jaundiced gasoline truck driver, who's just been told that his insurance won't cover the really effective stuff for his pancreatic cancer, spies a Ferrari driven by a 60-year-old teenager on the other side of a double yellow. All he has to do is turn the wheel a little bit to the left. If you're trying to live forever, it's not a good idea to live in a world where everyone has a reason to kill you.
