I would like to know how to get more game credits other than just selling stuff I have found and have heard that by going to the medical clinic and talking to the doctor and selling everything and then going to the markets and talking to expat and buying
it all back over again does get me more game credits?
If I recall correctly you need to do a quest for the Doctor first, as she is being blackmailed, before the financial incentive is there. Even then though you're not going to be getting huge amounts of cash.
You get credits from kills, opening crates, selling items and surveying minerals when on a planets surface.
Honestly, the economy system in ME1 is pretty busted. With all the loot you get on missions, if you just sell everything you don't need to the requisitions officer on the Normandy you should easily finish the game with 9,999,999
Yeah like Schuey said, you'd be surprised at how easy you start to garner credits once you're almost finished with your first playthrough. If you carry that same character into a 2nd playthrough, by the time you're halfway through it you'll have more credits
than you know what to do with.