Well, I'm not sure Larry has "millions" to roll around in. His latest book sold 6,100 copies in hard cover (see http://www.jasonsanford.com/blog/2015/4/yes-people-do-read-the-novels-up-for-the-hugo-and-nebula-awards.) Now, that understates sales by 40% and doesn't cover ebooks, etc., but I suspect he's making around $100,000 / year or so. Still good money but a bit shy of a million.