DrLaser,
Dang, you got lucky. That's pretty awesome to have a working P4 and box for 100 bucks. Unless you've got major karma points saved up from a past lifetime of charity work or something, I wouldn't expect this to happen on a regular basis. It's nice to get lucky once in a while, though.
Nice catch - the P4 is a lovely beast, isn't it?
For the life of me, I can't figure out why people selling high end vintage watches can't seem to figure out the batteries. It's not complicated. The batteries are not hard to find. It's unbelievable. I just don't get it.
-abe.