Batman was torn. Normally, he would have followed the money. The warehouse was interesting, and there was obviously more to it than met the eye, but it was a fixed location, and the money was moving. Right now.
But the boy was moving in toward the warehouse, and if Batman lost him, he'd have to spend valuable time trying to locate him again, and leaving him to deal with whatever he uncovered at this place on his own could result in disaster. Batman needed to stay close.
Moving around to the back of the warehouse, Batman watched as the boy put himself in a position to drop behind the guards and made himself ready to either follow or get involved at a moment's notice.