Kylian Mbappe may just be 20-years-old but he's already being touted as a future Ballon d'Or winner. 

While he was still a teenager, the Frenchman achieved what very few professional footballers will ever do - by winning the World Cup in Russia. 

The striker scored four times en route to winning the greatest prize with his country and officially announced himself to the world on the biggest stage of all. 

But in truth, he'd already gained quite a reputation as Europe's golden boy well ahead of last summer's tournament. 

After a breakthrough season at Monaco, Mbappe transferred to Paris Saint-Germain for a rumoured €145 million, making him the most expensive teenager in history. 

Since moving to the French capital, he's scored 39 goals in 50 Ligue 1 games and his stock is continuing to rise. 

He's impressed so much, that rumours of a potential move to Real Madrid have been constant throughout this season. 

Of course, if PSG are to part with a player that has the potential to be the best in the world one day, Los Blancos are going to need to cough up a lot of cash. 

Most recent reports from France Football suggest that Mbappe would cost Real €280 million - which would smash any previous transfer record. 

That would certainly be an outrageous figure to pay - but it's also one that reflects the current transfer market - especially for a player like Mbappe, who would be considered the most valuable in the world. 

But one man who doesn't think the Frenchman is worth €280 million is Brazil legend Rivaldo. In fact, he doesn't believe any footballer is worth that. 

"These days I read in the French press that the transfer of Mbappé to Madrid could cost €280 million," Rivaldo said while speaking to Betfair, per AS.  

"To pay a figure like that for any player is an exaggeration. Not even Messi, Cristiano Ronaldo or Neymar are worth 280 million."

As well as calling out the current state of the market, Rivaldo also suggested that inflated pricetags could have a negative effect on the players themselves. 

"I am convinced that some players do not think they should cost so much but try to justify it in each game because of pressure from the club, the press, the fans," he continued.

"That can sometimes torment you and does not allow you to get the best out of yourself. The high price of a transfer is always an extra pressure on your shoulders."