Why is there no supply and demand in this game? Ship and module prices never change. And if it weren't for the commodities nothing would ever change.
Because it would unbalance things to a larger degree. At least that was the story.
If I could by an Anaconda, and outfit it to 500 million, and then sell it for some of the normal markups ( 20-50% ).. I stand to make fairly ridiculous amounts of cash in a short period. This was an exploit in the early game : People bought in LRY systems or Jameson Memorial, and then sold in non-discount systems for stupid profits. The imbalance happened because people with lots of money could afford to sell fully outfitted battle-condas for stupid profit, buy a sidewinder and fly back, and do it again. Profits easily in the 50 million range per ship, per trip. That was way outside the proposed economic parameters and was subsequently 'fixed'.
Granted, if I have lots of cash now I can crush any local economy in my Cutter, but the profit isn't as insane ( 2-4 million per run, unless you're a slaver ).
So, we still have imbalance, but it's 'better' now. I just imagine it's like a no-haggle, galactic wide car dealership. The price is the price, unless someone like LRY or Jameson subsidizes the price. And then the dealer 'network' will only buy it back for the price paid ( minus the 10 percent, naturally ). It's been proposed that we be able to buy and sell to "Dodgy Daves Used Ship Emporium", where you'd get ships for a lot less, but of questionable quality or origin. IE : The hull has been repaired with tinfoil, or the class 6 FSD is really a size 3 thats been engineered to be "size 6 equivalent'. Or maybe a pack of elite bounty hunters show up one day and lay claim to their 'stolen' ship.
Personally, I'd like to see the game changed so I can fly a fully upgraded/engineered Corvette to Colonia, sell it for crazy profit, and then charter a trip back to the bubble. I'd also like to be able to sell to players, or take player generated missions.. but the fear is it would be abused, making new CMDRs with billionaire benefactors more successful, therefore leading to clans.. and EVE Online. I guess.
Anyway, don't expect it anytime soon.