Pretty much this; if its team-friendly, sure take him. If his projected value is between 3 - 6 WAR per season, and the deal matches that, you take that.
You just don't sign him to a long contract with big numbers off of one MVP season, that is a recipe for disaster.
They can also make it a creative contract as with JRod - base salary is w.e, but a lot of bonuses based on performance, athleticism, ASG/MVP bids etc.
If he loves the city/the team, as he claims, then he'll sign such a contract as the money quota will meet what he wants as long as he performs.