I love the White Star game. It's fast, it's fun and you need to make a lot of stuff up for your background (these are all qualities I also have.)
What if you wanted to make up an economic system or just guidelines for how much a credit can buy, how much a ship's overhead is and all that. I gave it a whirl inspired by Atomic Rockets of course!
If you're really making up a Cepheus Engine or 2d6 game out of whole cloth you can find a lot of this applicable.
Basically I started with the medium freighter and made it analogous to a modern cargo jet.
A medium freighter runs 15,000 cr.
A cargo jet costs 100 million.
Thus 1 credit is @ $6500 in terms of buying in this regard at least. Don't think too hard on it.
I assumed a cargo run takes about two weeks. There's a two week holdover at the port. That makes 26 cargo runs a year possible. The two weeks is just an average. It may be more or less on some runs.
I assumed a ship will last twenty years. Ship loans are for ten years and are double the price of the ship total.
Thus a loan for a medium freighter costs 30,000 cr.
Thus the monthly payments are 3,000 cr. a year or 250 cr. a month.
I assume crew, fuel and sundries are the same thus a medium freighter has 500 cr. a month overhead.
A ship can carry 50 tons of cargo so its cost to run freight is 500 cr. a month/50 tons = 10 credits per ton. This doesn't seem like a lot until we remember a credit buys what $65 does these days. A decent smart phone might be 10 cr.
Assume a 50% profit 15 cr. per ton. This price can vary ... a lot.
Our freighter will show 250 cr. a month profit. If the crew of two is working for shares the senior member gets three and the junior gets two or 150 cr. and 100 cr.
Assume spacers are middle class. That means the middle class make about 1200-1800 cr. a year. A spacesuit is a huge purchase costing one or two months' salary. Figure cost of living for middle class is about 50-75 credits. A fine meal out will run three to five credits.
Poor people probably make 25-50 cr. a month and spend 20-25 cr. for living expenses.
Middle class make 100-150 cr. and spend 50-75 cr. for living expenses.
Upper Class make 300 cr. and up and spend 250 cr. or more.
Passages run 100-200 cr. living people take up a bit of room.
Steerage is about 50 cr.
First Class is 500 cr.
Ships haul 1 ton of cargo per 300 cr. of price.
Warships haul 1 ton of cargo per 1000 cr. of price. They don't have to make money.
Sectors are 12-18 days apart averaging about 14 days
Say an Empire is six sectors in radius or 12 sectors in diameter or about 144 sectors total. A three month travel time is similar to the Age of Sail and doable. How many light years and worlds this is analogous to the age of sail. If a ship going to trade doesn't stop at every world for trade it reaches the Empire's fringe and those lovely colony worlds in three months. This makes shipping stuff really expensive: 500 cr. a month times 3 divided by 50 tons equals 30 credits a ton or about $2000 a ton. That's a dollar a pound. You'r'e not going to be getting a lot of low profit high volume cargos like foods and ores going to the colonies. You're go9ing to get finished products they need. The colonies will be shipping raw materials and luxury goods back. the raw materials find a market in the middling industrial worlds about halfway to the colonies and closer. The luxury goods find their market at the core worlds.
That is one way to work out an economic system. It's basic math expenses of the ship/amount of cargo it can shift. Varying the numbers lets your crew make as much or as few credits as you wish. Though delivering cargo in dangerous situations should definitely be worth more money.