Chelsea parted with a £32m transfer fee when they signed Diego Costa from Atletico Madrid in July 2014, as reported by BBC Sport.
Less than three seasons later, the Blues could be set to make a 33.5% profit on the 28-year-old striker.
Italian publication Calciomercato cite reports in Spanish magazine Don Balon which claim that Inter Milan’s Chinese owners are ready to offer Chelsea €50m – just over £42.73m – for Costa, who has scored ten goals and provided four assists in 13 Premier League games this season.
Costa has never played in Italy, but his success in Spain and England suggest he would be a Serie A hit.
In his last two seasons with Atletico Madrid, Costa played 66 La Liga matches, scoring 37 goals and racking up 10 assists.
Since joining Chelsea, he has netted 44 times in the Prem alone, adding 20 assists in 67 appearances.
Inter could do with a marquee signing to boost the mood around the San Siro.
The Nerazzurri currently sit eighth in Serie A, having finished outside the top three in each of the past four seasons.