Well, it is a list of the largest signing bonuses given to IFA. As neither Daisuke nor Okajima - both of whom went through a posting process for exclusive rights as well as hefty sums for their former teams - did not receive an actual signing bonus, they are not on the list.
If the list included draft picks, Rick Asadoorian might be on it. Remember him? Sox gave him a ton of money (like $6mill, I think) out of high school and he wound up being a career minor leaguer for 12 years...