Except for the fact that we would have exclusive negotiating rights with Jansen as he would be under our control for the next two years. Given that he's a former 16th round draft pick who has made less than $5 million in his MLB career so far, as @sveumruleshighlighted, I think he would be quite tempted to take the life-altering, guaranteed money right away, especially when doing so would enable him to play close to home in front of his family and friends.
To simply say "they go wherever the most money is" and "with their lifestyle they can live anywhere they choose to begin with" is very narrow minded and not necessarily in accordance with reality. Family and comfortability are often just as big of concerns for these guys as money.
FWIW, I know for a fact that Jansen maintains a home in his hometown of Appleton. So, sure he can live anywhere he chooses, but he's literally already chosen Wisconsin as one of his places of residence.