Pep Guardiola has claimed Manchester City would be "killed" if they spent as much money on new signings as Chelsea have over the last 12 months.
City's spending since Sheikh Mansour's takeover in 2008 has repeatedly come under scrutiny, with the club facing 115 Premier League charges for alleged breaches of financial regulations.
But Guardiola is adamant their approach had always been prudent, in contrast to the wild spending by Todd Boehly's ownership group at Stamford Bridge.
Chelsea have splashed out nearly £1 billion ($1.2 million) since the start of last summer.
City have signed Josko Gvardiol and Mateo Kovacic in this window for a combined £100 million, yet Guardiola was quick to show irritation over the astronomical sums paid by Chelsea.
"I couldn't sit here if we spent what Chelsea spent in the last two transfer windows - you would kill me," Guardiola told reporters on Friday.
"You will kill me. That is for sure. We'd be under scrutiny like you couldn't imagine. When people say just Manchester City and Pep Guardiola buy players, I didn't know I had a lot of money in my pocket to buy all the players I have.
"We have to see what happens in the market and if we can do it and to pay what we believe is fair.
"We wanted (Harry) Maguire and didn't buy him because we didn't want to pay. We wanted (Marc) Cucurella and didn't pay. We wanted Alexis Sanchez and didn't pay.
"In the end, we will pay what is fair to do it. Otherwise, we have the academy."
Guardiola tried to insist he was not criticising Chelsea, but the Catalan clearly feels a sense of double standards.
"They can do what they want," he added. "I don't criticise Chelsea for one second. I'm saying, if we do it, we are dead, all around the world. They can do whatever they want.
"If they want to spend, I don't know, £900 million since (Boehly) arrived, 900 more, 900 more. They have it. The business is the business. They sell a lot this season so they can do it.
"Everybody wins. Tell me the truth: are you enjoying a lot the transfer window? This player, the other one, every few minutes on Sky TV, a new player here, new player there. It's so funny."
Despite bemoaning Chelsea's spending, Guardiola said he was speaking to director of football Txiki Begiristain about their options in the window after star midfielder Kevin De Bruyne was ruled out for several months with a hamstring injury.
"We maybe need to add someone else," Guardiola said. "My opinion is I like a small squad. But the blow from Kevin changes the perspective. He is a very important player and it is not one or two weeks.
"We are not the only ones spending a lot of money in the last few years."