They may have caused his narcissism while trying to cope with his Asperger's and other issues by giving him too much reassurance and praise. I had a house mate with profound narcissistic personality disorder who was raised under a stream of parental worship and adoration about how pretty she was, how perfect she was, how smart she was, blah blah blah. After she grew up, anyone who failed to sufficiently praise every aspect of her being, or who tried to talk about any subject other than her, often caused her to feel seething rage. There is no cure for it, and psychologists just try to teach the afflicted to pretend to care about other people and listen to what they talk about. The amount of money is irrelevant, as she drove a cheap tiny car to her job as a hair dresser. No matter what their station, the universe is supposed to revolve around them and they get very angry when it stubbornly doesn't.
ETA: narcissistic personality disorder wiki. The symptom section is worth a look.
ETA: narcissistic personality disorder wiki. The symptom section is worth a look.