I bought and fully outfitted my first carrier last July with exobiology. I took a 15K trip out of the bubble in a long-range Anaconda, and used jumponium boosts to get back. It took about 2 1/2 weeks, totalling about 7.5 billion credits. You should be able to get what you need much faster.
Also available via Spire Sabotage.
Thargoid hunting is indeed wildly lucrative, I made over a billion in a few hours at a spire site the other night, and I'm a bit an AX noob. Otherwise I think the best money to be made is in the real human economy of the game, I made my first billion selling tritium to fleet carriers and I make most of my current billions selling Odyssey loot on mine.
exo bio is great made 1 Bill 6 hrs work best to go way out where no one has landed on the planet and you"ll get 5x the reward. e.g some specimens will score you 19 mill now multiply that by 5 you should get most systems offering up 2 to 3 planets that may have between 5 to 3 samples on the planet . I came across one system with 11 planets all with about 4-5 plants and because I was 1st foot on the planet that was all that x 5 .. big haul. That's how I got my F/C and change in the bank. Cheers Cmdrs
yeah, this game misses the real economy that is driven by real players, and not NPC.
smth like the one that EVE has. probably the best economy in the games I've seen so far.