How much vitality?
Vitality is a matter of balance with 3 other things. How hard/reckless you play, if you have Energy Shield or not (or intend on using Energy Shield), and balancing it with your mana requirements. Youll find most put at least 60 in, and in some cases, above 200+ in vitality at high levels. A lot of life can be obtained through items and charms (usually 200+ life), so its ok to budget for the lower end of your targets. If you find your dying a lot, then pump up your vitality a bit.