http://www.psacard.com/SMRPriceGuide...x?CategoryID=7
Not sure if the link above will work for you. It shows what cards would be worth after being graded by PSA. Normally, the premium cards are the first and last cards in a set, because most kids would stack them in order and then tie them with twine, hurting the #1 and last card. Those would also take the brunt of surface wear and dings.
If your friend has any Mars Attacks or Three Stooges, there might be some big value there.