Sir Alex Ferguson has admitted that he is 'amazed' at the fee paid by Paris Saint-Germain for Lucas Moura.
The French side signed the United target on a four-year deal from Sao Paolo on Wednesday for around €45m (£33m).
"I find it quite amazing that a club can pay €45m for a 19-year-old boy," Ferguson told the club's official website.
"To make a mark on everyone - to tell everyone that PSG are here - they've signed Thiago Silva from Milan and Zlatan Ibrahimovic.
"They must have spent about £150m in the last month. When somebody's paying €45m for a 19-year-old boy you have to say the game's gone mad."
Moura is expected to line up for Brazil in Saturday's Olympic final against Mexico at Wembley Stadium.
