Hello:
You were looking for ways to make the party earn less money (or seperate them from the money they are making).
1) Someone mentioned pirates.
A) The cargo hold gets hit and they loose some of the cargo
B) Damage to ship
C) Medical Expenses
D) Insurance goes up
"What do you mean you don't have insurance for your ship?!?!?!?!? No thank you I will get someone else to haul my cargo, THANK YOU!"
2) Each year the ship is suppose to be inspected by the Navy (or at a Scout Base) or something like that. "Can you say micro crack in the fusion unit. It will be at least a week to replace it, if we have the appropriate fusion plant to put in."
3) Someone mentioned taxes. The tax of 10% on everything should help a little.
4) Competition. Someone else notices that the group is making Tons oh money(TM). They go into competition with the group. "Sorry guys, only have a small amount of cargo left over. The other guys bought it all a day ago and left already."
5) Underworld wants their cut on the profit for doing buisness at THEIR port.
6) Can someone say REBELLION? This system is now a red zone by order of the Imperial Navy. Lets just see what you have for cargo. If it is something that can help the rebels you are aiding and abetting.
7) "Did you do a monthly maintenance? IF you did you would have noticed that the seal for the cargo bay was getting worn. You did not! Oh well, decompressurization of the cargo hold killed all the plants and wildlife. Oh and those drugs that says do not freeze or expose to a vacumn are now ruined. That machinery, well, we have to recalibrate it. That will take 20% off the profit.
"
9) "Sir, I am sorry you can not go to that cargo pad." In the background they see the security guy start to scream "HIT THE DECK HE'S GOING TO BLOW THE FUEL TRUCK!!" Suicidial worker just offed himself by driving driving the truck into the nice, shinny starship because it represented everything he could not afford in his miserable job.
10) "Hello Sir, I am doing contrabane and health inspection before you enter the system. Why are you all looking a little pale. Hmmm, let me take a quick sample here. SH*$(%*^&#(@) you con the crawling crud!!" Over his comm device, "CODE 1A I say again CODE 1A!!" As they see the SDB break the connection and stand by with guns locked on and charged.
Hope this gives you a few ideas.
John W. Fox