It is really annoying for the club chairman to intervene in the transfer. You can try to improve the positioning of the player, such as making him the main or core player, without paying him a high salary, just change his positioning. When the chairman accepts the other side's offer and you are not satisfied with the price, you can offer the player a new high-priced contract, and he will consider both contracts at the same time. If you offer a player a high enough salary, he will accept your contract. Then the transfer will be cancelled. The chairman's intervention will not succeed. As for how high a contract is to be cost-effective, you can file the contract first and read it again. If it doesn't work. After all, it is not easy for a small ball to keep a high diver.