The European Union is not entirely a non-governmental organization. Nor is it a supranational org, rather it’s a mixture of both. The E.U. enables theorists to belive in the concept of binding laws of a coercive nature.
The fact is that the union’s annual budget is around 130 billion usd (equivalent to National deficit of France). Basically, money does not make a difference. The E.U. does not rely on money but on policy. These policies are for the most part of the prevailing norm, that what comes out of the union is binding.
Furthermore, the authority of the union, does not mean that states are going to get along. The source of compliance, has nothing to do with economic resource or means of coercion.
There is a greater scope for the E.U. Trade, monetary policy, customs, fisheries, agriculture are exclusive jurisdiction of the E.U.