Martinez signed with Detroit today for 4 years/50 million dollars. I've posted a few things over the past few years trying to estimate fair value of players. One formula I came up with overrated mediocre prospects, another only worked for major leaguers but now I think I have one that will work for any professional player.
I have Victor Martinez worth 23.46 million using the safest rating. If a team that is rebuilding would have signed him, the most they should have paid is 22.70 million and a team looking to win now should have went up to 63.70 million.
I think the Tigers giving VMart 50 million is a fair deal for him and for the Tigers.
Just for another reference the Cincinatti Reds signed Dontrelle Willis to a minor league contract today. His safe number is 1.04 million. The win now value is kind of ridiculous at 17.43, but he could be worth that if he would ever return to the level he once was. The 3rd value is 1.04 million. I call it the win later value, which essentially any team could pay and not be getting ripped off too badly.
I just had a break through on this a couple days ago, so I haven't analyzed it too deeply, but it doesn't look too bad at the moment.