His posting fee is likely to be more in line with that of Kei Igawa ($26 million from the Yankees before 2007). Of course, once a team wins the posting rights, it still has to negotiate a contract. Igawa got a five-year, $20 million deal with the Yankees and thus far has been a total bust (2-4, 6.66 ERA in 16 games, and has been in the minors the past two seasons).
Could Iwakuma fit into the Mariners' plans? Considering their Japanese ownership, it's always a possibility, though the M's haven't signed a pitcher out of Japan since Kazu Sasaki in 2000.
Beyond Seattle's obvious need for offensive help, it appears to have one open rotation spot to fill.