It should get done. Deals do not get done over night and with the Messi saga going on we may not even be able to pass FFP with both of them. Depends if we have to pay a fee for Messi. I am sure we will know more after the Barcelona meeting.
I would just keep haggling and get the price down - if not he stays and we move onto Kounde/Carlos/Upemecano.
Koundé is too young and would need a lot of time to refine, Diego Carlos isn't really the best choice as his release clause is €75m, rather pay €80-90m for Koulibaly then, and Upamecano seems unattainable this window since he's just signed a new deal.