Ipswich Town manager Mick McCarthy has branded some of the Championship's summer spending as "outrageous".
Relegated Middlesbrough have spent more than £30m on new players, while Wolves paid a club-record fee of about £15m for Porto midfielder Ruben Neves.
Town have added five new faces so far, with Tom Adeyemi, Joe Garner and Emyr Huws joining on permanent deals.
"I am not complaining but I just do not know how it can be sustained," McCarthy told BBC Radio Suffolk.
"I think it is outrageous - but don't get me wrong if I had it, I would spend it.
"I get Middlesbrough signing their players because of the parachute payments. Bristol City spent £5m on a striker [Famara Diedhiou] and Wolves spent £15m on a holding midfield player for heaven's sake - they already have a £13m winger [Helder Costa, signed in January]."
Town have also signed Wolves defender Dominic Iorfa and Manchester City winger Bersant Celina on season-long loan deals.
Iorfa said: "There is like a new regime there at Wolves now. They have signed a lot of players so I knew that I might have to go somewhere else to play football. Luckily Mick gave me this opportunity."
McCarthy has said he is happy with Ipswich's own summer business and believes former Rangers striker Garner should be viewed as a "bargain".
"When I signed Joe Garner I don't think there was too much excitement about it," the 58-year-old added. "I think he is now being seen as a bargain considering what's being spent.
"I am pleased with what we have spent and the signings we have made."