I doubt if Girona will be able to maintain this performance in La Liga next season. Just like you said, football is business, and Girona would like to sell some of its best players to make a profit. The only thing that could make Girona not to sell some of its players is when they do not see the right price for their players. Girona management knows they can't repeat this performance next season, and they will not go far in the UEFA Champions League next season, so they will use this opportunity to sell some players to raise money for the club.
IN La Liga, practically there is only 1 ticket left to go to the Champions League, because the other 3 tickets are subscribed to by 3 teams every season, they are Real Madrid, Barcelona and Atletico Madrid. And this season they managed to become the team that got the 1 remaining ticket, and to be honest I didn't think they would be the team that could get that, because overall they are just an ordinary team that I have seen so far.
I hope Girona does not prioritize business in this matter, because this is an opportunity for them to show that they are also capable of competing in the Champions League. I hope they can prepare as well as possible, and can have a lot to say in the Champions League. I can understand that business cannot be separated from football, but what I mean is that they can balance team achievements and business, or in other words, both are priorities.
Every season there are always small clubs that can be a big surprise, such as Girona, which has now suddenly appeared with extraordinary performances, able to compete with other big clubs and even Atletico Madrid is below it.
I think maybe everyone will ask why Girona can be this strong when the club is only a promoted club, but we have to dig deeper to see how the Girona players perform, who I think deserve 3rd place.
This question is certainly often asked here, but one question that is difficult to answer is, can Girona maintain this kind of performance in the next season? Is Girona also able to compete with big clubs in the Champions League for the first time?
This question will be difficult to answer and in my opinion, if Girona is able to maintain its performance and perform well in the Champions League, there will definitely be many investors who will fund this club.