Single Player Concerns

In single player I have noticed a problem, as I advance along the storyline from time to time you have to sit and wait for the story to continue by gaining a certain amount of money to advance your level. by the time i reached Kyoto (mission 8 or 9, something like that) the amount of money I would need to get is just ridiculous. turning in captured pilots at the prisons seems to be the best way to make money, but since I am currently with the blood dragons I seriously doubt that's an option. and even if I were able to do it, the number of ships I would have to take down would put me stuck at this mission for weeks (considering that I can't play 24/7) is there any way to make several million credits in a few hours without access to a Prison? again, remember this is single player.

I was afraid this would be the response, two things, first, can I still access the prisons? I am fairly sure while I am with the blood dragons the police faction would be hostile, but perhaps not, second, even with doing that it will take me days, possibly weeks, to get enough money. I will need to nearly double everything I have acquired up to this point. so I was wondering if there is a more efficient means of making money. after all it takes a good 30 seconds to a minute, if I have impeccable timing and aim, to kill a single ship.