ok I read this and thought to myself gee I hope he is not thinking of doing anything stupid.
then the light bulb in my head went off, so I will answer your question seriously now.
I think it would be better to die relatively young a legend, beacuse in this question 'relatively young' has no definite time attached to it, so if someone dies a legend that means that they died too young.
If they became a legend in death then that would really suck.
If somone dies a legend then they are a legend no matter what age they died 20, 30, 60 ,100 ? it would still be too young.
If someone is a legend , can you not argue that they are still alive, until the time comes when they will no longer be a legend because all is forgotten.