$106,138,889 (before arbitration cases) - likely around $28 million in arbitration to payout
Nailing down an exact payroll number is difficult to do. FanGraphs seems to be the best outlet, outside of local reporting, to find these numbers. Currently, the Cardinals have about $106 million in guaranteed contracts and around $28 million in projected arbitration numbers.
The Cardinals need to get back to having a top-10 payroll in baseball. To do so, they'll need to raise their budget to around $200 million, which is about a $30 million raise from this year's Opening Day number, and gives them about $66 million to spend this offseason.
They can free up some more salary as well if they choose to non-tender or trade the likes of Tyler O'Neill, Dylan Carlson, or Dakota Hudson. They also may try to package some of their young players, or even an arbitration guy like Tommy Edman, for pitching help at some point.