I was thinking of an idea while looking at an atm. Then it came to me, why not an atm for credits.( If you do not know what an atm is it's a machine that you use to get your money.) Now the way it would work is by trading your materials in case you don't wanna die by a Dalek or something.(Even though they're everywhere.) So basically you would be able to trade materials to get credits, but it can't be cheap so it would be like 1 diamond equals this many credits it would just have to count what material it is like 2 iron for 1 credit but who knows. But that's just my idea that came into my mind randomly for the shop. If there are any questions please post it in the comments.

I forgot to mention: https://swdteam.co.uk/forum?p=thread&tid=281

Il edit

By the way, it seems a bit more of an "Ore Convertor" rather than an atm.

To be honest, it really reminds me of the Refinery from Starbound. The Refinery in that game turns Metal Ore (though not ingots) into Pixels (the currency of Starbound)