This topic tends to come up every so often. I always like to link a post from several years ago. There wasn't much math involved, just adding up numbers...and it's 4 year old data at this point so it might have changed slightly but it's still interesting. Just adding up the individual high column beckett price guide values and then looking at the complete set book value:
http://www.net54baseball.com/showthread.php?t=183323