Thats a pretty minor leak, judging about the muck built up on the case, looks to have had seepage for a long time. I see drips on the pan bolts too and a gasket between the pan and block. I never use a gasket, they leak more frequently than using RTV as the factory does. maybe have a fluid/filter done and reseal the pan. give that a shot. I also notice some wetness around the output seal for the driver side axle. a new seal may be in order. But from what I see on a 13 year old van, the man that sold you the van isn't trying to hose you over. Infact whose to say that it just didn't start after you took ownership. I sold a K-car to a nut job. I rebuilt the engine and it ran perfect. 2 months later, she was all over me, making threats, having people call pretending to being a lawyer and more vicious things because she claimed the transmission crapped out. The car was towed and impounded because she refused to pay the tow bill and insisted I take car of this problem. First a used car from a private party is and "as-is" sale. 2nd, how could I possibly predict the trans would have failed and who's to say it didn't get beat on. Anyway after a couple months of this, I finally filed a restraining order. About 6 months later, I saw the car forsale at the towing company so I contacted them. Turns out the outer CV joint failed, she never paid the bill so they tow company fixed the problem and put it up for sale. My point is that a car is a mechanical device and things will just fail for unforseen conditions.