According to Jim Callis, Drew Gilbert signed slightly under slot, as did 2nd rounder Jacob Melton. Our boys at AstrosFuture have all of the details.
There is a pot of roughly $1 million to get Ryan Clifford, ranked inside the top 100 on several sights (i.e., a 2nd or 3rd round talent).
Given that many considered Gilbert to belong in the top half of the 1st round, and Melton was a fringe, 1st-round comp. type pick, adding Clifford would really be a shot in the arm in terms of talent infusion. It’s a bit of a coup that both of these talents signed under slot.