I think the problem the OP is posting has to do with a lack of monetary policy. Since there is essentially an infinite money supply, it will be quite inflationary. The rarer credits are, the more they are worth. Since there will be an infinite amount of credits, they lose their value. It is simple macroeconomics.
Their in-game solutions to take money out of the money supply usually are bunk (mounts, repairs, etc) as by end game those only usually take small percentages out.
There is no real way around it unless the devs state that (random figure) 50,000,000 credits are in the money supply per server..then you would probably run into welfare/redistribution of wealth arguments.