It is true that Barcelona is in a financial crisis. However, the Barcelona management will do their best to take Lewandowski in the team. If necessary, they will want to take Lewandowski in the team even if he takes a loan. Because Xavi's goal is to win the title next season, they definitely need a striker like Lewandowski. However, Barcelona may not be able to spend too much money now.
Barcelona problem is related to the bad management and the choice of players and their high wages. They need to reconsider the performance of their players and improve the squad. For example, De Jong can make them get Lewandowski +/- let other players leave or be loaned to reduce the charge..
Being clogged with financial issues will make any coach unable to guarantee any title or even a stable performance of the team.
Selling de jong in my opinion is not an accurate solution to solving barcelona current problems, maybe the money obtained from selling de jong will be used to buy lewandowski, but in my opinion, in fact Barcelona will not be able to win if they only rely on lewandowski without support other quality players, even if barcelona got lewandowski it would make their attack line dangerous but what about the midfield or defense which actually became fragile when de jong left?
I think Barcelona will only add new problems if they are desperate to sell de Jong and buy Lewandowski at a high price.