As a 'retired' player who is unable to delete his planet, I've been playing around with it a fair bit.
There is a way to make it profitable, and furthermore, you also get to inflict your own personal damage on the top 100.
Personally, I target the top 3 players of the top galaxy (look at me, no co-ords
) and can expect to get about 500k of each resource each morning.
I have Security as Priority 1 (increasing my stealth bonus) and use 10 agents on the first planet (scan for resources first, it only costs you 9k for all 3), 2 on the second and 1 on the third. well worth it
Keep in mind here that my score was just bashed down to 60k (was 200k before
) I don't know if there's some sort of formula relating to sizes.