Yes, the way I imagine it is quite overwhelming, a galaxy split between humans and enemy aliens, and human factions going to war with each other and attacking or defending from the aliens and you in the middle doing your thing. That alone sounds hard to code...
As for the other part you would design in house all parts, so instead of findind "Astral runner legs" you first research them (by reverse enginering from enemies or rewarded from a quest), produce a blueprint and incorporate it into any mech template you are assembling for selling. The assembled mech will have then variable stats depending on used pieces and how much prototyping you did, quality of the engineers you are employing... and might turn out with some kind of bonus or fault that will decrease or increase price and perfomance. Malus like missaligned, unbalanced, overheating... or their opposite bonus. Then with the money from selling, you can refine your existant pieces to be cheaper, faster, simpler to produce... so you can potentially refine all base components and release a higher performance Mk2.
If the mechs are just for sale you wonĀ“t really care about their stats, but I want to attach an autobattler so you want your hardware to be able to destroy the opposition, thatĀ“s a better encouragement to get better models rather than just getting a bit more of money per sale.
The player must do their best to get new pieces blueprints with better base stats to use on their models, that would be one of the main progression elements, I have many other ideas to flesh the concept but I dont want to cover the post in a wall of text.
