Manchester City chief Garry Cook insists there is a long-term plan tied to their spending.
"This isn't really about spending," said Cook. "I'd like to just make sure the message is clear that we're investing in the future of the football club.
"The investments that we're making currently will define the football club for the next 10 years.
"I think when you do that to compete with the top four in the Premier League, you have to invest to reach those new levels."
City's riches have come from the Abu Dhabi United Group, who took over the club last year and, asked when the spending will stop, Cook insisted it was totally up to Hughes.
He continued: "It stops when Mark feels that he's got the right quality of players in the squad.
"Definitely we're limited by virtue of a window of opportunity to buy those players. So I think the players that we've acquired will add strength to the squad and that's the ambition."