Played a while last night. Fully upgraded my multi-tool, dirt cheap upgrades - max I paid was like 130,000u! Found a nice little trick;
One example I had was a 19-slot multi-tool, and then I found a 21-slotter. So what I did, knowing full well I wanted it, was break down all available upgrades on my current one, which some how forces the game to drop the buying price (usually around 20,000u), and then buy the upgraded tool. I then broke down all the upgrades on that one, and re-fitted it out with newer/better ones. Sometimes I lost out, in that some materials were fewer than I had before the upgrades - from breaking them down. I dont think the game gives you ALL the components back, only a portion of them.
Also found another crashed ship, was the same amount of slots as my current one, so I just "accepted" it, broke down the upgrades, and took my old ship back.
Bonus from that.... I found an upgrade that included a Vortex Cube. What that meant, was when I transferred the Vortex Cube to my inventory, it changed it from a 1 of 1 item, to a 1 of 100 item, meaning I could have up to 100 Vortex Cubes in the same slot!!! MASSIVE SCORE - STACKED VORTEX CUBES!!!
I then traveled back to my "Vortex Cube Planet", and went hunting for Cubes. Have like 8 million units now! Still a long ways off buying a 30+ slot ship (like 20 million units!!), but I'm on my way.
Here's what I meant about the stacking Vortex Cubes (note 4 of 100);