The Drudgery of Starship Operations

Operating a starship in the Known Worlds isn't all fun and games. There are consumables (food, water, oxygen, ammunition), preventative and ongoing maintenance, landing fees, berthing fees, loading and unloading fees, and everybody's favorite complaint: taxes!
Consumables are the cheapest (and arguably most important) ongoing expense. 1 Firebird/week per person will keep your air and water topped up and supply average quality food and drink.
Maintenance for a ship the Revelator's size will run you 40 Firebirds/month. A good ship's engineer can cut that cost down.
Spaceports charge landing fees based on a ship's size. For the Revelator, that will typically run you 40 Firebirds.
Then you have the berthing fee, which is again based on the ship's size and charged per day. For the Revelator, that will average another 40 Firebirds per day or fraction of a day.
Loading and unloading is in the purview of the Stevedores Guild runs 1 Firebird/ton of cargo moved for standard (first come, first served) service. A rush job or overtime can easily end up costing 3-5 Firebirds/ton.
Lastly we have taxes. Each of the great houses, major guilds, and church sects have taxing authority on their planets, granted to them by the Emperor. There are 2 different taxes a starship owner or operator should be aware of:
First is the cargo tax. Most authorities tax any cargo destined for their system. If you're just passing through on the Jumproad, you don't owe, but many a ship owner has been harassed to pay the cargo tax when docking in-system, even if they have no intention of offloading or selling their cargo in that system. The cargo tax is typically assessed at 5% of the value of the cargo. Most authorities will accept a bill of sale for the cargo as proof of its value, meaning you pay the 5% tax on the price you bought the goods at, not the price that you sell them at.
Because there's another tax, a sales tax, that gets the local authorities their cut of the sales price of the goods. The sales tax is typically 25% of the sale price of the goods. 10% goes to the local authorities, 10% to the emperor, and 5% to whoever controls the planetary agora (typically 1 of the major guilds).
There are a number of ways to avoid or mitigate your tax burden:

1. Only haul goods belonging to someone else. That means the owner of the goods is responsible for the cargo tax and sales tax.
2. Join the ranks of the emperor's Questing Knights. A member of the Company of the Phoenix is immune to taxation when crossing feudal boundaries. This exempts members of the Company from the cargo tax entirely and from the 10% of the sales tax that goes to the local authorities.
3. Smuggle. Don't reveal the full contents of your cargo hold to the authorities and figure out how to sneak the smuggled goods off your ship and too a buyer without the authorities noticing.
4. Cheat. Keep 2 sets of books, with bills of sale for values below what you paid to buy the goods or what you received for selling the goods. Success here frequently requires use of the next strategy on the list:
5. Bribes. Bribe customs inspectors to undervalue your goods or overlook some quantity of them.