Nomura says the A's offered a four-year, $15.25MM deal, for an average of $3.8125MM per year. The team was using Kei Igawa (five years, $20MM) and Colby Lewis (two years, $5MM) as comparables, while Nomura countered with Hiroki Kuroda (three years, $35.3MM) and Daisuke Matsuzaka (six years, $52MM). The A's pointed to their $19.1MM posting fee, but Nomura wanted to keep the pitcher's contract separate (presumably since Iwakuma wouldn't see any of the posting fee money). Nomura remains open to a deal since the sides have until December 8th, though he suggests the A's are now "hunting two free agent pitchers." He finished by noting that the team's offer to Adrian Beltre "was just a PR" move.
Susan Slusser of the San Francisco Chronicle broke the story yesterday; her blog post was updated with similar information prior to Nomura's barrage of tweets. Her source pegs the posting fee at $18MM. In either case, Iwakuma would have cost the A's over $8MM a year. In my opinion, that commitment was already plenty risky.