I don`t think that San Jose has at all a bad list of players taking part of an ATP250. On the other hand, I don`t find it ethic at all that the tournament director has to make it public that he offered a player a certain amount of money to be part of it and the player decided that the amount is not enough. Maybe he didn`t offered Delpo the same amount that Rotterdam offered (if so) to Djokovic, Davydenko or Soderling to play there. Or maybe Delpo didn`t wanted to play there and asked for much money. After all, we only heard the tournament`s director position.
Tournament directors AND players usually try to keep the appearance fees a 'secret', but of course it leaks out 'through the grapevine', once in a while. DelPotro is a GS-winner, a true top dog, so his appearance fee should be in the 6-digit range at least. Asking for too much money is indeed a reknown way of finding yourself in the position of not having to play a tournament which you don't want to be playing... but of course tournament directors may end up being pretty pissy about it, hence their not-so-positive reactions about it.