While financial reasons may indeed be true for Catalonia, Basques are another thing. Their nation is the last remains of the original European people that were wiped out by indo-european nations. Basques have nothing in common with the rest of Spain (or Europe) other than being conquered by them so long ago.
Their language is not indo-european, they are the last remains of original Iberian people (not to confuse with Spanish people). Of course genetically they would probably mix with shitloads of other nations, just like everyone in Europe. But from that point of view, there are no real nations anywhere anymore.