I think Nova is the rarest source
I would have to say that ore is the rarest resource, I can never find any when I need it.
I find nova easier than ore...
Kryllith
Ore. No question about it.
Definitely ore. Most of the random Naboo maps tend to have more ore deposits on them than any other maps. Kashyyyk also seems to have a lot of ore deposits as well.
Ore of course. You can get nova by capturing the holocrons and making trade with your allies
you don't even have to consider trading and holocrons
if you just look at the concentrations on the map
Ore crystals come in patches of 250 each sqare..
Nova crystals are 800 per square
so say you have an Ore patch of 4 squares, thats only 1000 ore
compared to the 2400 you would get from a Nova patch of 4 squares.
And Nova is MUCH more common in massive patches of 10-12 squares, Ore's highest is normally about 9 squares, maybe more sometimes, but it is commonly found in groups of 2-3 squares