My take on this: I also agree with Per and others that the line "I need more supplies before I can tackle those guys" has an implied "I'm not ready yet, I'll get it done when I have everything I need." It seems a bit redundant though to have two "Be right back" lines in the dialogue. Perhaps the original devs intended for this line to lead to a node that does give supplies but just never got around to it and thus sent it to the same node as the line "I'm working on it." We don't know though and we cannot really make assumptions. Thus, I feel you should not remove the line, but instead alter it to something along the lines of this: "I need more supplies before I can tackle those guys. I'll report back to you when I have some news." (or something similar.) No need to remove a line just because it is redundant; diversity in dialogue is always good. Fallout(s) have always had numerous dialogue lines lead to to the same result and they are just there to give some flavor to the conversation.