About a week into starting to play, I stopped receiving Terriforming Devices. I routinely wait until my artifact points are well over 20k before starting to cash them in and stop just under 10k so I don't get a ton of smaller artifacts. Either way, I've got that same original mission ("The Terra Project") waiting to be completed but can't get any devices to finish it off. Have TDs become more expensive (last I read they were 10k) or just so uber rare and I should just keep trying?

Just very very rare some NPC also drop what is needed for the mission but they are also both rares.

Terraformers are VERY rare artifacts and you are very lucky to be getting them. i have only gotten one. They are worth 5k points but are rarer than most other artifacts.

One question, how do you have an artifact bar over 20k? That should not be possible unless you spent money in the game. There is a planet limit based on rank, and the artifact bar limit is based on planets. You should not be able to have that much till at least rank 80.

I'm at rank 145 and have received a grand total of three Terraformers in the time I have been playing this game. They are very rare, but the reward from the Terra Project mission is definitely worth it. Just add to the mission whenever you get lucky with another Terraformer.