Alternatively, you can poach outposts from all the land grabbers that overextend themselves. It takes a bit of micromanaging in terms of intel gathering, but it is quite easy to snatch a newly colonized outpost and quickly move the 25k CO off to your own colonies.

Even if it's not economically sound in the long term, war is often necessary (and fun). One thing I have realized so far is that you may be screwed in terms of the resource value of the planets you have access to at the beginning of the game. After fully probing my sector, I have discovered a number of players who were lucky enough to start in or near systems with 2 huge jovian worlds and 2 terran worlds. Meanwhile, I started with an ice world that produced ZERO ore of any kind, and a couple of dumpy rock worlds, and found nothing much more compelling nearby. If you find yourself in this situation, you will need to act aggressively. Don't allow traders to monopolize the jovian planets! You have much to gain by taking them for your own! I increased my RO supply by an order of magnitude overnight last night by taking a jovian outpost from a nearby idle player.

Also, I for one won't stand for this scourge of Traders infiltrating every unclaimed corner of my empire! I don't have the energy to manage a billion outposts, so I probably won't make it to the end game, but I won't go quietly!