It's currently quite bad. Billions of credits is the norm in the game at the moment. Mining is way too profitable compared to everything else. And most things are quite profitable by themselves.
How else could it be? If there's a set of activities which are profitable and a set of activities which are not, players are going to gravitate to the profitable ones and mostly do those. If no activities are profitable, then no-one ever gets out of the Freewinder.
Therefore inevitably after playing for a while players end up very rich, even without exploits, bugs, etc. I've never used any of the famous "get rich quick" schemes, and have only done a couple of hours of mining since 3.3 ... but I've been playing a long time, so I have a couple of billion of spare credits which just showed up, over time, as I played the game.
Certainly Frontier need to adjust some of the older earning methods - rares trading especially - so that their profits keep pace with other changes in the game. But the idea of people generally being able to make money isn't going to change.
I know some people are against reducing the credit output, but with the current state of the game, credits are worth absolutely nothing. Might aswell remove them completely and give everyone every ship/module they need at any given time.
If I was lead designer on an Elite-like game, then I think one major break from tradition I would do would be "no credits". Run the whole thing on a patronage-and-reputation system where if you want a particular bit of kit, or some special tuning for your ship, you work for a patron who'll give you it (or more often loan you it), or you barter something you've found (a new ELW, for example) for it.
Problem is, I don't think most players want an economy. I think they want to collect numbers...the faster and easier, the better.
This. The current in-game trade economy has a fair bit of detail to it in terms of supply and demand for various goods, effects of BGS states on those, etc.
However the baseline supply and demand levels are set such that it would take probably a hundred times as many players in game to seriously affect them in normal circumstances. It's not going to happen.
It occasionally gets to be relevant for specific goods in very limited circumstances - trade CGs in Colonia, the Witch Head repairs, Palladium more generally for a while - but very rarely. And even that limited amount has attracted a lot of complaints.
It wouldn't be that hard conceptually [1] to go from what they've got to an economy where a broad variety of in-demand goods needed to be regularly shipped to every station to avoid bad things happening. All the components are already there - they'd just need joining together a bit differently, supply/demand quantities would need reducing significantly, and the effects of economic states turned up to 11. BGS groups supporting factions over their systems then need to make sure their trade networks are good.
But I think the problem is that if the economy is made relevant, the cost is that most players then have to care about and maintain the economy, even if trading isn't what they want to do. Making the economy relevant without losing the fun I can't work out how it would be done.
[1] Fine detail of balancing, that would be
really difficult. But they could wrap it in a bit of storyline and pretend at least some of the booms and busts were intentional, if they monitored enough to see them coming a week or two ahead...