Brian Marwood believes criticism of Manchester City's big spending is "laughable" and insists the Blues have a long-term plan.
Sir Alex Ferguson, manager of their city rivals United, has claimed City are fuelling unsustainable wage inflation.
Yet Marwood, City's football administrator, believes the signings are part of an "investment" in the club's future.
He explained: "A lot of people are misinformed, they form opinions without knowing the true facts.
"It's become laughable, some of the comments about our football club. We are comfortable in terms of what we set out to do and the direction we are heading.
"We are extremely fortunate to have owners who invest in the club, in all areas. It's for the future.
"Eighteen months ago we were fighting a relegation battle but our ambition is to be playing in the Champions League."
Sheikh Mansour took in a match for the first time since the Abu Dhabi Group took control of the club in Monday's 3-0 defeat of Liverpool.
And Marwood told BBC Radio Five Live: "Everyone appreciates what he's done for this club.
"We've seen (at other clubs) a lot of people come and very quickly go and leave a trail of destruction.
"Sheikh Mansour, (chairman Khaldoon) Al Mubarrak and those invovlved want to be in it for the long haul. They want to put a structure in place they can enjoy for a number of years."
On Milner's arrival, Marwood continued: "It's a bizarre market because no-one's spending any money at the moment.
"The price for James is what it is and Villa weren't prepared to sell him for less. If we want him we have to pay it. I believe we are investing in the club and James will only become better. That comes at a price.
"We believe now we have a squad for the next four or five years. We will make tweaks to the squad because you have got to have the situation where you are freshening things up in certain positions."
Marwood, who insisted that Emmanuel Adebayor and Shay Given are staying at Eastlands, believes City's rivalry with United is healthy.
He explained: "Why shouldn't there be great rivalry between United and City?
"They've been the benchmark club try to aspire to. We want to get to that level and I love to think we could surpass it - but we've got a long way to go.
"United have done it over a number of years and kept it going for the best part of Sir Alex Ferguson's tenure. We're just embarking on our mission but we want to get there and sustain it.
"Our fans have had an enormous amount of disappointment and false dawns. We're trying to take the erratic behaviour of the club away."
