I think it's in our best interest Barcelona to sign Sanchez. City want Sanchez as a midfielder and they already have three top attackers, so I doubt they'll go after Kun at all and they'll be after a midfielder, not an attacker. Chelsea seem like they're going to buy Falcao for ~30m eur, so with him and Torres I doubt they'll be after Aguero. With Atletico refusing to sell Aguero to Real and with Milan and Inter already having more than enough top attackers, we remain the only candidates.
In any other case in which a 2nd team is willing to pay big money for Kun, except Real, we're not getting Aguero.