Unlimited credits
When your character arrives in Korriban, sees the Sith academy. Beyond the tombs- there are archaeologists- and make sure Juhani is going with you. There will be one more character to the left, in the Valley of the Dark Lords called Dark Vesser.Ask him who he is and Juhani will recognize him.
This character will go to the canteen. Now leave Juhani and see the canteen. Talk to him and tell him that you will kill him so he will begin the fight. When we finish with your life you will only have to register your belongings to find 150 credits and a laser saber.
Now, get out of the canteen and go towards the entrance of the Sith academy. Then he goes to the canteen again, Vessen will have reappeared and you can kill him again.
Whenever you go to the canteen without Juhani you can fight this poor Sith. Where is the unlimited loan trick? Well, as we say, Vessen has a saber that is valued in 2000 credits. Every time you need money you just have to come, kill him and then sell his saber.