Arsenal manager Arsene Wenger has described Paul Pogba's £100m-plus price tag as "completely crazy".
The Italian is due to return to Old Trafford for a world record fee that could reach as much as £122m in the summer's biggest transfer saga.
Manchester United are set to complete the deal in the coming days following weeks of negotiations between Pogba's current club Juventus and his outspoken agent Mino Raiola.
"It is completely crazy if you cannot afford to pay it. If you can afford to pay it you can justify it," said Wenger when asked about the size of the Pogba deal. "It is completely crazy if you compare it to normal life. That is for sure. But we live in a world where every activity that is worldwide makes a lot of money.
"Football has become a worldwide competition and that is why clubs can afford to do it. Does it make sense in the way the player can give you that investment back? Nobody ever could calculate.
"Since I am in this sport I always thought the record cannot go higher and I was always wrong. Maybe in a few years it will be 200, 300, who knows?"
Wenger's record signing in the Gunners hotseat is Mesut Ozil, who joined for £42.5m from Real Madrid in 2013.