Well, both, obviously.
But in all seriousness, if I had to choose, I think I'd rather be 25 with $1k.
I really don't need a trillion dollars, at any point in my life (and certainly not with too few years left to do anything with but the tiniest fraction of it). I don't need a billion dollars, even. I figure $20M would allow me to do anything I wanted to do, with a healthy cushion in case anything went wrong. (Well, with $20M, even if I were to triple my spending habits, I'd likely still die with more money than I started with.)
I'm not sure that I fear death, but I do recognize at middle age that time is finite, and there are so many things to do in this world. Even with close to nothing as a $1k-holding 25-year-old, I could strive to make things better for myself, and likely look forward to a lifetime of experiences. At 95 that would nearly all be behind me.
Put another way: if I was 95 and had a trillion dollars, and there was some highly advanced, crazy-expensive procedure I could undergo to reduce my biological age down to 25, even if I'd only have $1k left over afterward, I expect I'd do it.