Real Madrid and Girona cannot be compared because the difference in quality between these two teams is very different, but Girona this season has the confidence and chemistry of the players which is quite close so that they can produce good performances throughout this season.
Until now I have not seen any difference or decline in Girona's performance.
Girona managed to bounce back after three not so good match results, but that was not enough to change the position of the standings and they had to be patient waiting for Real Madrid to fall, which seemed difficult to happen, but Girona has become a competitive team this season and any team cannot underestimate they.
Rayo Vallecano succeeded in holding Real Madrid to a draw but they couldn't do that to Girona, in fact Rayo had to suffer a fairly heavy defeat 0-3.
Girona played very well in this match and the red card received by Rayo players in the 76th minute made it easy for Girona to score two additional goals so they could win with a landslide score.
I would say the payment you get should be different, or at least that's what I assume. I understand that there could be some small changes, and nothing major but even the reputation plays a role. Girona being second or third doesn't matter to them and they would be happy, shame that they were leading the league and looked like they would have a Leicester type of story, but third is amazing for them.
However, being third behind Girona is not acceptable for Barcelona and that's why it matters, doesn't matter even if they get all the same things, it would still be a shame for them and fans would feel humiliated and their biggest rival Real wins the league so they would be mocked a lot for a whole year until they do better.