just found a Dysillon while mining :p so I'm rich enought to keep it for a week, and by this time I'll earn enought cash doing lvl 30+ missions.
I agree it's powerful in terms of size/power ratio. I'm gonna keep it on, however I don't come capturing planets everyday (since I have it, I became more incline into hacking haha :p).
So the solution for me is just lvling up and colonise a mining planet, as I focused alot on research, I was weak in terms of economy.
as you said it's more powerful than things not even researched ... Maybe the mission availability should be put at lvl 30 and not before ... I'm wondering. At least there should be some kind of info about upkeep, because I was very happy to complete the mission and stunned when I saw my upkeep rose x6
... Double effect