I had an idea of adding a universal shop to the game. This would be on a separate tab - and would have minor artifacts and ship items on sale. Ship improvements would be for sale for an extremely higher price - but still on sale for players that haven't researched that tech. So if I haven't researched the tech needed for Auto Cannons - I could still buy them for three times the price. Some items could be limited to level - like you need to be atleast level 10 to buy Auto Cannons in the first place. Artifacts on sale would translate artifacts for credits - but they'd be extremely high priced to choose which artifact you wanted - rather then the random artifact collection - minor artifact would be on sale but everyone would have to pay a large price for even common artifacts. Minerals/credits now would be more/less valuable based on this - and all minerals/credits would become greatly more valuable overall.

You could even try a communal trade area where players could buy/sell their artifacts for what they think it's worth in credits. I want credits so I put my spy probe on the market for 100,000 credits for 1 week - so people can buy it and I can gain the credits. However if I cannot sell the artifact in - then I can take a tax or penalty of 10/20% of it's value (it's value based on the creators in credits) to keep the artifact I tried to sell. So if you don't sell the artifact you try to sell within a week you could be penalized based on the value of what you try to sell.

If the prices are demand driven than only the top ranked 5% would be able to buy anything. Just think of paying like 50 million credits for a containment missile. If it weren't, then the higher levels could probably find a way to take advantage of it. Maybe if it only had crap artifacts it could have set prices.