Per Baseball America's Jim Callis.
This is obviously a big step for the team, which very recently emerged from bankruptcy. The new ownership group was approved late last night in Minneapolis, and they've made a decisive and resonant first move. It's roughly double MLB's suggested bonus for the slot, but evidently the Rangers believe Jackson's worth that kind of commitment. It makes me wonder if recent reports that he's risen to 6'4 are more than just hyperbole on his part.