How much fuel does it take to travel in an orbit? I assume this is yet another example of idiotic journalism. Also, Lagrange points are not a new topic. A Google search will give you several "L5 Society" pages.
Once you get to one of the two dynamically stable Lagrange points, it shouldn't take any fuel to stay there, but at the other three, which are dynamically unstable, it would require occasional small maneuvering thruster burns to null out the effects of pertubations, which would otherwise cause the spacecraft to drift out of the unstable equilibrium.
At least I think that's the case....
It depends upon where the orbit is. Orbiting anywhere other than a Lagrange point is unstable and the orbit will decay without using fuel to stay in place. Think about all the space stations that have crashed.
The Algoresat, sitting in a warehouse and ready to fly on his inauguration day carries enough onboard fuel to stationkeep at L1 or is it L2 for several years. If they can stay inside a small radius, all that is needed is a puff of gas now and then. There are already a couple of satellites there, though, and I wonder if they can safely avoid each other or if it matters since they would hardly be moving relatively anyway. L4 and L5 wouldn't need any fuel at all, they will orbit forever.