Space Traders At a Glance
First, it should be cleared up that 'space trader' is a bit of a misnomer. The player doesn't have to be a trader at all. He can choose piracy, bounty hunting or even something like exploration which doesn't offer any profit at all. A player can decide to go to war against a certain faction/race, or to be its staunch defender. He can also combine philosophies and be a pirate who only assaults the ships which belong to the enemy of whom he defends. The freedom is there for him to choose his own destiny. Early in the game he might have to trade with itty-bitty margins to try and upgrade his ship.
Now the decisions come in - try for combat upgrades or more trade upgrades? The combat usually tends to be more exciting if dangerous. Destroy a ship and you get the cargo for free, there's the profit. If you have a license to defend a race (which, of course, can be bought for a very reasonable price…), you might even get paid a token fee for destroying enemy craft.
A trader, on the other hand, would probably upgrade his cargo hold to carry more, the engines to cut down on time and invest only a slight sum for defenses. Naturally, he'll keep a lot of the money back to be able to afford trade goods.
Unfortunately, not every system (nevermind every base) has the upgrades you want. You might have to fly a few sectors over to find the pirate base and get their engine and maneuverability upgrades, then fly a few more sectors to find a good weapons factory that's selling a gun or missile that you want. Too bad that the shield dealer with the great shields is 15 sectors back! While for a mercenary or pirate this isn't as much of a concern, a merchant is loathe to give up his hard-found good trade routes, just to fly off for some equipment. While he can continue to upgrade his cargo capacity, eventually the increasing costs of doing so will finally make it worthwhile to take a trip to one of those dread pirate bases and upgrading the engines to gain more speed. Who knows, maybe along the way a new trade route will be found?
What Do I Do With All This Money?
Good question. There is a lot to spend on. Weapon, shield, cargo, engine and maneuverability upgrades are all available. While weapons and shields cost a set price for each item, and once you buy (or earn) the best shields you're set, the cargo, engine and maneuverability upgrades cost geometrically more with each purchase. The first upgrade might cost X, and the next costs 1.5X, then 2.25X and so on. Hence, the returns are diminishing with each purchase. The first (say 1000 credit) upgrade improves speed as much as say the 7th (150,000 credit) upgrade will. These aren't hard figures, just here for illustration.