The selfmade millionaires under 40 are statistical outliers ;)
(Not strictly "auto"biographies, but most of them have ghostwriters anyway)
"Virgin Rebel" (Richard Branson)
"Return to the little Kingdom" (Steve Jobs)
"Enter the Dragon" (Theo Paphitis)
(There are lots more, but they are in my bookshelf at home...)
George Orwell's Down and Out in Paris and London. He gives up his bourgeois lifestyle to live among the poor. I'm not sure he started anything at the end though. Besides himself, with a wider perspective of the world.
Lots of well off kids bum around being "poor" while their parents pay their expenses. Actual poverty is an entirely different thing and involves going hungry and having your electricity turned off.
edit: I don't know about "to-riches" but this is the turnaround I often think about. I guess it depends on your objectives.