If they want more, money can be added.
Godforbid they might want Puig (the only club where he potentially could be of transfer worth for Barcelona) but also Griezmann, De Jong, Ilaix, Dest and of course Messi, potentially, apart from those mentioned.
Getting Bernardo would be too good to be true, and Laporte could be perfect as well.
That's the problem.... we don't have the money they'd want. Silva and Laporte still have years left on their contract. Laporte is probably worth 50m and Silva is probably worth around 60m in today's market. Roberto is probably only worth around 25m and Dembele is probably worth around 40m, especially when they only have 1 year left on their contract. We'd have to throw in 55m to 60m, which we don't have. As I said, they don't need Dembele. They may take Roberto, but only for a rotational player.
We may get Silva and Laporte next year, but we're only signing free transfers this summer. Depay will probably be our last signing. Realistically, if we do want to sign a big signing this summer, we'd have to let Messi go. We can't keep him here and expect to sign big players.