18hr retainer ventures--which ventures can be gotten via GC, dailies, etc--will typically result in Allagan pieces. Bronze, silver, and gold depending on level, and those are purely for money.

You can also open a craft and work on desynthing, which is when you break down old gear/some materials/fish for either base components or some rare items. Arguably you can say this isn't a "facet" but at times you can get clear demimateria which is purely for the sake of selling to NPCs for raw gil, so its half-n-half.

Otherwise I can't think of much else that's a natural 'facet' for money outside of marketboard manipulation and watching.