If the offer from the Red Sox really was 4 years, $70 million, it's just a ridiculously low offer.
The 5 year, $82.5 million contract that the Yankees gave A. J. Burnett after the 2008 season set the bar at the time for #2 pitchers. That was 5 years ago, and there has been huge inflation in pitcher salaries since then.
That same year, Derek Lowe got 4 years, $60 million, and he was going to turn 36 that season.