This is how I got all the gold bars. Sorry its kind of hard to explain how to do it, I'll try again. To get out with all of it and quicker you need to convince Ehaja to come down and meet you face to face. After that you will get an option to betray him and trap him down there. You do this by walking to the sheild doors because Ehaja will power them down so he can walk though them. But you can only go though the farthest shield door which is in the farthest right hand corner of the room. You can't go thought the nearest shield door without being detected. But you have a limited amount of time to get to that door, because Ehaja is walking to the vault and once he gets there he will activate the shields to the doors and you will need to restart. To get there in time you need to use a weird method. With a stealth boy on and crouched, open the vault door walk out and close it now face forward drop gold in front of you, the gold will now have been dropped a few feet in front of you. Now you walk maybe 2 yards in front of the gold. Since you dropped the gold it will allow you to quickly walk 2 yards infront of it as you are no longer over weight limit. Now you turn around and pick the gold up, try staying far in front of it thought, and turn back around and repeat this process until you get thought the farthest shield door. If you get though the shield door your home free as a nearby elevator will take you to the fountain. Hope this is more clear. Doing this I got 37 gold bars which I believe to be all of them. hope this helps anyones trying to get away with all of them. Also 37 gold bars is worth 389943 caps. But trying to sell to merchents drops value to about 5500 caps each.