So I had this thought. Mari Di Angelo is presented as a well off woman, probably uppar class. So when she dies, her money is left to her children. But they never end up claiming it.
So when Nico turns eighteen, he resurrects a lawyer and claims his long forgotten inheritance by claiming to be a descendant. But by now the inheritance has rose in value since the 1940’s. So Nico is actually really rich but nobody knows it.
Will solace finds out when Nico calmly buys him a top of the range apartment for the both of them to stay whilst at college.
The seven finds out when Nico starts funding their business and educations.
Nico, who walks around in beaten up converse, a ratty ripped pair of black jeans and a bomber jacket two sizes too big, is actually a millionaire. He buys a really expensive motorbike which he maintains himself and drives to his classes.
He funds quest expenses and buys the equipment for camp half blood and camp Jupiter. He sets up a charity to aid in finding new demigods.
Basically rich Nico being the adorable person he is.