Marotta says the Belgium international left the San Siro in search for a fat cheque at Stamford Bridge.
Lukaku brought an end to a two-year stay in Serie A to return to the Premier League to feature for Chelsea before the closure of the summer transfer window.
The Belgian had failed during his first stint in West London which made him move to Everton and Manchester United before he joined Antonio Conte’s side in the summer of 2019.
Lukaku redeemed himself in Italy and went on to become one of the deadliest marksmen in the division. His rejuvenation forced Chelsea to pay a mammoth €115 million for his services.
Inter Milan have replaced Lukaku with Eden Dzeko, another proven scorer who is getting the business done for the Nerazzurri.
“Lukaku was sold for €115m and we bought Dzeko for free. On the pitch, there isn’t much difference,” said Marotta, speaking to Corriere della Sera.
“Lukaku left to double his salary, in Italy these figures can’t exist.
“Today, we can’t make important investments, I wouldn’t be allowed to sign Lukaku for €75m (£63m/$87m). We need reduced and specific investments.”
The former Anderlecht man hit the ground running at Stamford Bridge but his goalscoring binge seems to have come to an end as he is yet to score in his last seven games for the Blues.
His poor scoring form has also been aggravated by the injury he took in Chelsea’s 4-0 victory over Malmo on Wednesday.