There is a new book out by Hwang that they post snippets of from time to time on Sports Collectors Daily
http://www.sportscollectorsdaily.com...s-value-cycle/
That could help your friend determine how to actually monetize some of the newer stuff. I'm going to go the more old fashioned route and find some raw cards of "key rookie cards" and submit for hopefully good grades. Basic gist is look for the Bowman Chrome Rookie refractors paralleled to 50. Some of them get so out-of-whack (IMO) that it's better to wait a year to buy them on the prospects you think have a shot at becoming the next big thing. Like right now, I'd be considering Raimel Tapia. Rockies hitting prospect that BaseballProspectus has been drooling over for two years, but still not a mainstream prospect.