There was a fair bit of hand-wringing from Premier League rivals when United agreed to bring Paul Pogba back from Juventus in the most expensive transfer of all-time.
Just a year on, the deal worth up to 110million euros (£93.25million) pales into insignificance compared to the 222million euros (£200.6million) forked out by free-spending PSG to secure Barcelona's Brazilian star Neymar.
Senior figures at United had long spoken about their expectation of the summer transfer market being crazy and Mourinho praised executive vice-chairman Ed Woodward for making key additions before it fully took grip.
"I think we were very clever," Mourinho told The Times
"We thought that something could happen that could change the market forever.
"Normally the last part of the market is less expensive, but this season, after Neymar, everything changed and changed for the worse in terms of prices.
"I think Lukaku on August 31 would have been £150 million
Matic would have been £60 million or £70 million
Neymar changed everything.
"If the biggest transfer in history had still been Pogba, I think Philippe Coutinho would now be in Barcelona at £101 million
People look to the £200 million figure now."
United were able to snaffle Everton striker Romelu Lukaku for an initial £75m and Chelsea's Nemanja Matic for £35m, with their combined add-ons potentially adding a further £20m.
Victor Lindelof has yet to make the same impact since arriving from Benfica for an up-front payment of £30.75m, but could also prove smart business in a summer Mourinho hoped to end with the addition of a wide man capable of playing at wing-back.
Inter Milan's Ivan Perisic ultimately proved beyond them but the United boss is happy with this squad, albeit the Portuguese believes he needs one more summer to perfect it.
"We're going to fight against very good teams, but we're going to try," added Mourinho, whose side sit atop of the Premier League after three matches.
"I have said three (summer) transfer windows is what I need to have the team I want to have, the team I think can bring Manchester United to the top of English football and to close the gap to the top of European football again, and I still think we need that third transfer window, but I'm not going to wait for the third transfer window to try to reach it."
Source : PA
Source: PA