you can cheat by using the command console, here's a tutorial
or do it legit, there are many tips on this forum: http://futuremark.yougamers.com/forum/showthread.php?t=95653
"With that in mind, the easiest start is the "humble trader".
You get a mercury transport and a small argon ship for courier work, defence etc.
I started with the trader game, and after about a month, playing for 4-5 hours every night, I've got about 20 million credits.
I've now got 3 mercury's and a couple of M3 fighters.
If you can start as trader, get yourself down to "ore belt" (head down from argon prime), you can trade ore and energy cells here for ages and build up a few million in no time at all. "