I would try and do a deal with Madrid to give them the entire 200m for Griezmann in January. This would allow them to replace him with Costa who Chelsea may price out of a move without the extra money. Basically swapping Griezmann for Costa + 150m isn't bad business for Madrid.
The other players Barca are looking at are decent but they aren't Barca standard. All of them would struggle to start for PSG, Real, Bayern or even Chelsea, City and Utd.
Barca can soldier on until January. Ultimately they may lose the next Classico (badly) but it makes far more sense having a lineup of Griezmann, Suarez and Messi instead of Coutinho, Suarez and Messi going into the business end of the season where even without any more signings they will still most likely be in all the cups and close enough to Madrid in the league.
Ofcourse if money isn't an issue then scrap what I have said but I think it's pretty obvious it is an issue.