Personally I won't sell the collection for any money - these girls are priceless - emotionally, but every person may have their very own reasons.
Perhaps the guy just decided to quit, as he says, not using the program anymore, lost the interest, suppose ... but don't want to throw all the stuff just away either.
So, how to be?
My hypothesis was rather technical. In principle such a transaction should be possible, if not the rules of course ... For example, if you'd buy my PC with VGHD and other cool, but licensed stuff installed on it, you'd be able to use them with no problem, 'cause that's the right computer and no one can prevent anyone to sell its PC
IP address changes shouldn't be used as a factor, because people are traveling around the world a lot today, working abroad and so on...