Get 400000 at the start of the game:
complete the first mission - deliver computer parts 

mission 2 collect scientist, when you get back to destination 
before you contact your empoyer sell the shields + guns on the ship 
you are flying and you get around 400000 credits - you only get to 
fly the ship for that mission anyway.

Mission 3: When going to investigate the broken gate in Brennans Triumph. 
Having problems getting close to the nacelles to
investigate without being blown up by the SQUASH mines? 
Simply stop by the Argon Free Trading system just north of the goner 
temple (in cloudbase southwest) and purchase a few Fighter droids. 
When you get to brennans triumph, release one droid at a time and tell it 
to FOLLOW one of the squash mines, 
(make sure your far away when you do this!!) wait a few minutes and
before you know it most all of the mines will blow up. 
You may need to send another droid or two to clear the rest of the mines, 
there are alot of them.

Hint: I was only able to do this once but on your way to investigating
Brennans Triumph, the first sector west of cloudbase southwest 
I was able to make a pirate eject from his ship by firing at him. 
I guess it was coincidence that an Argon Titan was there firing too, 
simply shoot the pirate in his space suit (Eh, he'd do the same thing 
to you if he had the chance ;) ) and take his ship! 
I made the mistake of not going back and saving this progress 
however and died later on. 
A pretty good catch considering there's no chance in hell to take on 
this ship at the beginning.

Hint: You can "capture" any ship of classes TS,TP,M3,M4,M5 by firing at it, 
but I think it´s a marrer os chance in x2 then you can pilot it, 
use it as a wingman or just sell it.
 - kajanov