To Rafael Benitez and countless others, the answer is simple: "Money, money, money. The transfer was 100 per cent about money."
The charge of greed is one that City, and all associated with them, cannot escape. Carlos Tevez, persuaded to swap red for blue in Manchester, John Terry, his head apparently turned by the riches on offer at Eastlands, and Barry, delaying his dream of playing in the Champions League for at least one more season, all stand accused of measuring bank balance above trophy cabinet.
Barry, of course, is adamant his new club do not represent a sinecure, little more than a sky blue pension plan. It is easy to scoff, at least until the subject turns to the tortuous saga of last summer's abortive move to Liverpool.
The disappointment still rankles. In a year when he thought he would be winning over the Kop, Barry instead had to win back the Holte End. His move was not about wages. City offered him what he wanted, simply because they wanted him.
"I found Rafa Benitez's comments a bit disrespectful," Barry said. "By that stage my decision was made and people should move on. There was genuine interest from Liverpool and I think he's probably just upset I chose City.
"I've been in the Premier League for 10 years, more, and the money I've been paid is phenomenal compared to your average, everyday working man. You live and work away from normal life anyway, so money's not a big factor.
"The difference was that City made me feel wanted. Liverpool had a chance to buy me last season but failed to pay the money, and only found it this year when they knew someone else had reached an agreement.
"There was a feeling of being let down. Excuses were made about things going on behind the scenes and in the boardroom, but I came out of it looking like a bad person. It took a long time for me to get back into the squad at Villa afterwards. It was tough to deal with.
"That's why there's nothing better than a club making you feel wanted and getting a deal done in days. It's not about money, it's about the chance to be part of something big from the very beginning at a club who really want you."
Speaking in the opulence of Abu Dhabi's seven-star Emirates Palace hotel – as a guest of City's new sponsors, Etihad Airways – Barry knows he is an easy target. But his new club's plans for global expansion are proof enough for the England international that he is where he should be.
"Most people would snap your arm off to do what I've done, but for me to be able to say my career was successful I need to have some trophies and some medals in my cabinet when I finish," Barry said.
That would be achieved quicker if he was joined at Eastlands by Terry. Hughes "looked me in the eye when I signed and said he was confident of getting players like that, and in quantity", Barry admits, "and that they've even gone for him shows City mean business".
Such a coup would surely cast off the image of City as the foolish, naive nouveaux riches, established in those regrettable few days, in the immediate aftermath of Sheikh Mansour bin Zayed Al Nahyan's takeover, when Sulaiman Al-Fahim, quickly dismissed, spoke of £134 million bids for Cristiano Ronaldo.
Hughes is clearly working to a plan. Barry has been taken from the bosom of Aston Villa, most likely City's strongest competitors to break the Big Four cartel, and from the fingertips of Liverpool. Tevez's arrival hurt Manchester United, the departures of Terry and Adebayor may yet damage Arsenal and Chelsea. Hughes is systematically weakening his opposition.
"Taking their best players hinders them and strengthens us," admits Barry, "but it's not about signing the very best players, it's about gelling them together."
The spending spree must excite, though? "When Tevez has just trained for the first time and you turn on the TV and suddenly Adebayor's in talks, you think: 'They're not messing about, are they?' Even for a player, you wonder what's going to happen next."
