Sorry just new here.Found it yesterday.My question is:
Does killing Contreas from Camp Mccaran lower NCR Fame?

Well I have no idea if it does but:
1. Save game.
2. Kill Contreas
3. See if you lose any NCR rep.
4. Reload.

I would expect so, but if no one sees you do it...

(To my knowledge there are exceptions to the rule but generally if you are unseen by anyone when you kill someone you lose no rep. The only exception I know of is the NCR embassy guy (totally forgotten his name...) and that may just be a glitch).

As Gabe said. Save, kill and find out!



eta: By unseen I mean hidden, you have to one shot them and be crouched.

No it doesn't.

he is a bad guy, sort of. instead of killing him, you can turn him in. if you are into guns, he is worth more alive.

Worth more not turning in, not just leaving him alive.....if you turn him in, you lose him as a real merchant, too.

Side note: if you kill him and then turn him in, his corpse will be put in the jailcell. Hahaha....

I always leave him alive and ignore that quest. He's worth more to the NCR selling me ammo for companions who go through it like candy fighting bad guys than he is dead to give Karma to my reputation.

Naw, do the quest and leave him alive, to improve his inventory and get a discount.