Worth pricing what the treatment in the question would actually be, on current evidence, before deciding what to trade for it. Best replicated result in any mammal: rapamycin in the NIA Interventions Testing Program, 23% more median lifespan in male mice and 26% in females at the top dose (Miller 2014), replicated across three sites. In any mammal outside a laboratory: nothing yet; the first controlled lifespan trials of a drug against aging are in pet dogs (TRIAD with rapamycin, 580 dogs; Loyal's STAY study with LOY-002, 1,300 dogs), reading out around 2029 to 2031, and the FDA's veterinary center has already accepted lifespan extension as an indication for two dog drugs while its human side has none. So the realistic version of the offer for the next decade is a drug that might add between a tenth and a quarter to remaining life, approved first for dogs, with the human number a decade or two behind; which species gets the first approval (mine): https://manifold.markets/w0lph/which-species-will-get-the-first-re

For an anti-aging treatment that made me X years younger, I'd trade the retirement benefits I'd accrue by working during those X years. Unless anti-aging made me permanently young, I would not get rid of all retirement benefits.