Are these years at the end of your life added on? Or like in the middle? 2 more years where I stay more or less as I am now I might give up an inch or two, but 2 more years in diapers at the end ... nah I'm good.
To get to the meat of the question, I assume these would be healthy years, not just extra senility. If you offered me that deal, I'm definitely gonna be a really prodigiously long-lived dwarf.
I do not fear death or the afterlife so I don't necessarily want to have that longer lifespan. Especially since i have no way of knowing how those 2 years are going to be spent... they could be total agony