Arsene Wenger admits Arsenal will have to pay a minimum of £70million to replace Alexis Sanchez.
The Chilean is in the final year of his contract at the Emirates and has refused to sign an extension.
Arsenal agreed a fee with Manchester City on deadline day but the deal didn't go through as the Gunners failed to land a replacement.
City are expected to reignite their interest in January with Arsenal reluctantly accepting Sanchez will not stay beyond this summer.
And Wenger has conceded the Gunners will have to splash the cash to replace their talisman.
"You take Sanchez into the final year of the contract and you sacrifice £60m-£70m income and at the end of the season, you will have to buy somebody for that amount of money," he said.
"It has a huge price. At some stage, you have to make a decision, you have to sacrifice."
Wenger went on to discuss the problem with players entering the final year of their contracts, with Mesut Ozil's future also remaining uncertain.
"Today, we have 107 players in England who go into the final year of their contract. It is a complete rotation and change in the way people see their career," he told beIN Sports.
"Other clubs, because the transfer market has gone up so much, do not want to pay so high prices.
"The amount of money is disconnected to reality. Dembele was £15m last year and this year, £150m.
"No matter how well you work on the pitch, you cannot make a player go from £15m to £150m.
"The calculation between investment and what you can get back, is gone. It's whether you can afford to buy or not."