Virtuous wealth

I've been reading some of Plutarch's Lives on and off recently...
Plutarch tells us that Lycurgus, who established systems of law and economy in ancient Sparta, believed that the happiness of a man consists in the exercise of virtue and not in power or wealth. The biographer describes the Spartan lifestyle that Lycurgus instituted (redistribution of wealth, meritocracy over plutocracy, communal eating and working for the good of the state; this must surely have influenced Marx and Engels) but makes little mention of Sparta's serendipitous use of helots, state-owned slaves who allowed citizens to pursue virtue without needing to worry about chores; this must have influenced Stalin.
Anyway it makes me wonder, if happiness cannot be achieved through power or wealth but only through virtue, does that make virtue and wealth mutually exclusive? While Lycurgus redistributed wealth to correct Spartan morals, the economy had been based on inheritance of land rather than entrepreneurship. But in a capitalist free-trade economy if you give others what they want, you could plausibly become virtuous and wealthy at the same time: this would constitute a Thatcherite beatification of Rupert Murdoch and Bill Gates.
Of course, these two are a long way from sainthood, given the way Gates treats his competitors and Murdoch controls information to further his own political ends. And if they were to give up some of their wealth to fund clean water, vaccination and literacy their virtue would be even greater; but that is true for all of us. So at what point does our wealth make us unvirtuous and therefore unhappy? And at what point does our poverty make us virtuous and therefore happy? Is there a practical way for us to become happy without giving up our comforts? Or is that just called income tax?