In my view, the motivating factors in Vito's life were security and control. His wealth was aimed at buying the power and influence to assure security and control. The kind of materialism we identify with people of great wealth didn't register with him. I think Tom was very much in Vito's model: Sonny picked him up off the street, where he was homeless, starving and suffering from an eye infection. Just being accepted as a member of a big, secure, warm Italian family must have been paradise to Tom. He probably used his own wealth to assure his kids' education, and to leave them with an estate they could build on. But, I'm guessing he, like Vito, wasn't motivated to live big and flashy.