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.
Lewandowski has only been with Barcelona for one season, and in his first season he was able to show something extraordinary. He can adapt quickly and he has also contributed a lot to bringing his new team to the La Liga title this season. He really wants to be at Barcelona, and I don't think he will be quick to leave this team he wants.
Barcelona is like a new home for Lewandowski, he is very comfortable with the situation at Barcelona which allows him to immediately adapt to the style of play used by Xavi. Lewandowski can still be relied on even though he is already 34 years old, he managed to bring Barcelona to win Laliga and won the top scorer in his first season.
Lewandowski period at Barcelona has just begun, he won't be leaving Barcelona any time soon, especially since Xavi still needs his energy to win several prestigious trophies next season. Barcelona will appear in the Champions League with the status as Laliga champions, need new resources to be able to compete with other strong teams, Xavi will be very busy in the transfer market to bring in several players so that his squad is stronger than this season, moreover he has just lost an important player Busquets and Alba.