How much money does the radio man require for compensation?

On the zeppelin, Indy can offer to compensate the radio man if he catches him while the radio is destroyed or if he's stolen the wrench and the locker is open. However, I'm not particularly good with fisticuffs in the game, so I've never had enough money to satisfy him. Examining the game files shows that there are strings in the game for when the radio man accepts the money, so presumably there is some amount that he will accept. How much money is enough to satisfy the radio man?