Arsenal boss Arsene Wenger concedes the club made a massive financial sacrifice in keeping hold of Manchester City target Alexis Sanchez.
The Chile international was heavily linked with a move to the Etihad Stadium during the off-season, having entered the final year of his contract in north London.
City eventually agreed a £60 million deal for Sanchez, but the Gunners' failure to pry Thomas Lemar away from Monaco saw the transfer fall flat on deadline day.
With the 28-year-old forward now able to leave the FA Cup champions on a free transfer in July 2018, Wenger acknowledged their decision not to sell will prove very costly.
"You take Sanchez into the final year of your contract, you sacrifice £60m-£70m income and then at the end of the season you will have to buy somebody for that amount of money," the Frenchman told beIN Sports.
"So it has a huge price. So at some stage you have to make a decision you have to sacrifice one or two [players]."
Wenger lamented the rising fees in the transfer market, with Neymar and Ousmane Dembele becoming the world two most expensive signings when they moved to Paris Saint-Germain and Barcelona respectively last month.
"We have today 107 players in England who go into the final year of their contract," he said. "It's a complete rotation and change in the way people see their careers for two reasons.
"One, all the players expect higher wages because they anticipate inflation; [and two] because the transfer market has gone up so much but clubs do not want to pay so high prices on transfers for players who are good players but will not change their life.
"The amount of money is completely disconnected to reality and the truth. I give you one example: no matter how well you work as a football coach, Dembele last year was €15m, this year €150m. No matter how well you work on the football pitch you cannot make a player go from €15m to €150m.
"But the calculation between investment and what you can get back has gone. It's just: can you afford to buy or not?"