I honestly don't see a problem with Discovery's economy. In all reality, I have more money in my fighter than my large train. Why? Because it's not all too hard for me to take on the capital ships (I guess I'm a skilled very heavy fighter pilot, right?). Of course I don't take on Osiris class battleships, I take on Bounty Hunter Destroyers (equally hard in their own right when there is like 5-6 of them).
Trading to earn those big bucks comes at the risk of piracy by the local pirates that run parallel to the trading routes and that's just the risk you have to put up with. Now yeah I'm on the server hours at a time, but I generally make my income from killing NPCs and selling the pilots at the battleship and selling the equipment that they drop as well. Sometimes I'll run to Cambridge Research Station to sell the Nomads that I'll occasionally pick up. But that's just me I suppose, always sharpening my skills in a fighter instead of trading 24/7...