Edit: already answered that you can commit suicide if you want.
Yes, i absolutely would take the 500 years then. Why wouldn't you (unless you are really old already and would be stuck that way for 500 years, that would be rubbish).
It sounds great actually, you get to try out multiple different life paths, partners, friends etc. Loads of time to try different artistic pursuits etc etc.
and if it proves too long you can just jump off a cliff.
i think it is probably only worth it if you are between 18-50 (if you are being strict about staying the same age you are currently)
This, and after 100 years or so you'd have enough money/assets to take the other 400 pretty chill and only need to make enough to eat and pay immediate bills.