United are on the verge of completing a transfer for the 23-year-old that could cost them in excess of £100m.
"If you are making money and have to pay big money for the best players, why not do it?" Robson told BBC Radio 5 live's Sportsweek programme.
Manager Jose Mourinho wants the deal to be completed before 14 August.
No deal has been announced for Pogba, who has been on holiday in the United States since losing the Euro 2016 final with France against Portugal last month.
Juventus coach Massimiliano Allegri has said he expects the midfielder to be at training on Monday, although reports in Italy say Pogba has flown to the UK for a medical.
Manchester United have not responded to these reports.
Pogba played at United for three years before rejecting a new contract and joining Juventus for a £1.5m compensation fee in 2012.
He won the Serie A title in four successive seasons in Italy and has established himself as one of the most highly rated players in the world.
"Sir Alex Ferguson allowed me to watch training as Pogba joined the first team squad [as a teenager]," said Robson.
"I was very impressed with him. He was a good build, with a good temperament.
"He is the type of player we need.
"He is similar to Yaya Toure in the sense he is very good going forward and can score spectacular goals.
"I am not sure he is a great defender but he does an adequate job."
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Former Manchester United captain Bryan Robson says he has no problem with the club breaking the transfer world record to re-sign Paul Pogba from Juventus.