This has really become a nightmare of big teams these days. Because they are continually losing important members of them. After Benzema's sudden departure it is normal to see people starting to talk about the probability of Lewandowski's doing the same as well this summer. However I don't feel like Barcelona will lose Lewandowski at least for now. Because I haven't seen even a single rumour about this. We are talking about Lewandowski in the end. If there was such intention by a team we would have learned about that already. But Barcelona had better create a Plan B in case of his departure. If they don't they might have big scoring problems depending on their not being able to sign a proper striker.
I also think that there is no reason for Lewandowski to leave Barcelona in search of super-profits to Saudi Arabia, following such stars of European football as Cristiano Ronaldo and now Karim Benzema. Still, I think that Lewandowski has not yet said everything he wanted in La Liga and therefore he still has to stay at least a season, especially since he seems to have a great relationship with Xavi both personally and professionally. I was much more surprised that Luka Modric decided to stay at Real Madrid, and did not leave in search of big money to the Arab sheikhs.This is completely correct , I see no reason for Robert Lewandoski to leave FC Barcelona immediately after that he signed just this season. Well, I feel like he moved to the la liga to win a trophy not that alone alone but also the Ballon d'or.
Money isn't everything, although it's good idea. Luka Modric is a Real Madrid legend he knows. Real Madrid right now seems happy, at least they cannot sign everyone.
Of course not all players are after making a huge deal of money right away. For example Messi could have chosen an offer from a Saudi Arabian team instead just as he stated the same thing as well. However he didn't and wanted to go on a different path instead of doing that. At least he could have joined an MLS team whose ranking is better but anyway.
Modric and Kroos would have also left for such team if they wanted I assume. But they wanted to extend with Real Madrid for one more season.