Pricing a free agent is never an easy task, especially since all it takes is one over-zealous owner to blow away everyone's expectations (see Prince Fielder to Detroit).

But if CBSSports.com's Jon Heyman is right, free agent hurler Zack Greinke could be headed for a record payday.

Heyman spoke with several baseball execs who suggested Greinke could be in line for a contract of "at least six years" and worth up to $25 million per season, which would bring his total windfall to $150 million.

Heyman points out that that would be the richest contract ever signed by a right-handed pitcher, topping San Francisco's Matt Cain, who signed for $127.5 million in spring training.

It would also top the $24 million per season that Cole Hamels just got from the Phillies, which is currently the highest price of any of any pitcher in baseball.

While Greinke's numbers might not quite compare to Hamels', Heyman makes the case that Hamels probably cost himself some cash by opting to re-sign with the Phillies in-season rather than opening himself up to a bidding war on the free agent market this winter.

Heyman lists the Angels and Dodgers as the main competition for Greinke, but also says the Rangers "loom as another threat in the Greinke market."