Anthony Martial became the most expensive teenager in football last summer when Manchester United bought the then 19-year-old from AS Monaco. The basic numbers of Martial's deal were known at the time, but a bonus program makes the deal bigger than originally thought. On Tuesday the contract was leaked by French outlet La Figaro, and United could wind up paying as much as $87 million (€80 million) for the French international. 

 €50 of the €80 million is guaranteed while the rest is based off a bonus program, according to the Mirror. The guaranteed money is paid in two installments, €20 million on the date of the transfer, and €30 million at the end of the 2016 season.

The remaining €30 million is broken down as follows: €10 Million will be paid to Monaco if Martial scores 25 goals for United. With 8 so far this season it seems possible Martial will pass that mark. €10 million will be paid to Monaco if Martial appears in 25 matches with the French national team, and a further €10 million if Martial is shortlisted for the FIFA Ballon d'Or award, according to FOX Sports.

The 20-year-old Martial is under contract with United until 2019, if the club were to sell Martial before his contract expires, Monaco would receive 50 percent on any capital gains between €60 and €100 million United gets for the forward, according to the Independent.

It is hard to say if Manchester United overpaid for Martial. €80 million is an inflated price tag for a forward who has only scored four times since Oct. 21. However if United end up paying the full amount to Monaco, it means Martial has developed into an elite footballer, fulfilling three impressive bonuses in his deal, in which case paying €80 million over four years will seem like a bargain. Imagine a measly €80 million dollar transfer fee for one of 2015's Ballon d'Or nominees. €80 million over four years for Lionel Messi, Cristiano Ronaldo or Neymar? Seems reasonable.