Everton are looking to add a striker before the transfer window closes.
Costa has refused to play for Chelsea following a bust-up with Antonio Conte, and is angling a move away from Stamford Bridge.
The Spain international, who has 16 caps under his belt, prefers a move to his former club Atletico Madrid, but with the Rojiblancos currently under a transfer embargo, they cannot sign him in the summer transfer window.
The Merseyside club have been strongly linked with a loan move for Costa, but the report suggests that Ronald Koeman is weighing up a £30 million move or higher for the striker.
The Champions value the 28-year-old at around £50 million. The report adds that talks are expected to be held today when Everton face Chelsea at Stamford Bridge.
Chelsea are planning to hold talks with Everton for midfielder Ross Barkley, who is also a reported target of Tottenham Hotspur.
Everton have bolstered their attacking department but Koeman is still looking to add a striker to his ranks. The Dutchman wants the club to make every effort to bring Costa to Goodison Park before the transfer deadline.