It looks like Inter will be quite active in this transfer window. But would they spend a lot of money on a single player? I don't think so. Even if their financial condition is good now they would still be stingy I think. Because they aren't a team that splurge on a random player. Only if they believe in a player to be the transfer they are looking for then they decide to use their funds much more than the usual. Currently they are trying to sign a goalkeeper and striker as a priority.
For the goalkeeper position they are thinking of Sommer to fill Onana's place as Onana is about to join Manchester United soon. I guess Sommer would like to come rather than being Neuer's substitute.
For the centre-forward position Lukaku is still one of the strongest candidates. As the player also wants Inter it is only up to a reasonable deal between Inter and Chelsea.
Lukaku deserves to be signed by Inter Milan because his career is very bright there. Lukaku sees that his performance in inter Milan looks great, which is why he also preferred to stay in the team even when he was offered a significant sum of money to go Saudi Arabia. I believe that Inter can do anything to obtain a good striker who will improve the team,They will want to avoid having a terrible performance because they are also participating in the champion league.
In addition, Onana has put a lot of effort into helping inter Milan, and he deserves to be recognised as the team's best goalkeeper. However, I don't believe that will cause inter Milan too many problems because, regardless of the situation, inter will have a quality goalkeeper in place before the league season begins. Finding a quality keeper may be challenging, but selling Onana won't have a negative impact on inter Milan, in my opinion.