On that scale probably only one
On that scale there is probably only one resource we have they could want, the planet itself. That is assuming their habitable range is anything like ours, we have no grounds for making a guess on that likely hood. Even a civilization with faster then light travel might not be capable of creating planets. And even if they can, removing us might be a lot cheaper.
Of course all of this is built on the assumption they have reasons and motivations similar enough to ours that they can be understood. I tend to think this is likely at the level of basic resources like liquid water and oxygen atmosphere. But it is very likely their emotional and less rational motivations would be incomprehensible to us.
Jay
