Want to get rich in SWG? Become a weaponsmith, and do it well. Resources are your key here. Put the time and effort into finding good ones, and keep obsessive anal-level track of them on an Excel spreadsheet. You won't see a return for a while, but in 3 or 4 months of doing this you'll find that you're starting to make the best weapons on the server, ones that people pay a LOT for. Set yourself up with a merchant and get listed on the global map, and by all means advertise through whatever means possible.
I did this and in 7 or 8 months' time I was making at least a million credits a month, easily. Had I spent more time on it I could have been making a million a week, I'm sure.
The problem of course is that this gets old after a while. Eventually I quit and came back to my bard in EQ. :)