Originally Posted by zakhal 
I assume 5 mil included not just art but lots of other design stuff they can use in fallout3. Not to mention all the coding that was done. I doubt they would be stupid enough to pay that much for som games name and few clips of art. Surely they are going to use great deal of what they got from purchase.
The 5 mil buys them the right to develop spinoff titles with their partner companies, as they've done with the Elder Scrolls Travels series.