Scavenger’s Scrap Bonus Effect
Scavenger is a useful Trait to invest in early on, but becomes significantly less useful after having it for a while and once you are mostly done crafting weapon levels. Having the extra scrap lying around to purchase large numbers of buff potions allows you to use them more frequently through the game, especially when you are still gearing up and can use the extra hand, without having to sacrifice your advancement in gear level.
Once you’ve cleared the campaign a few times through, it might be worth considering using an Orb of Undoing to reset your skill points and move the 20 here to something else that helps farm XP faster, which is the real long term grind.
How to Find the Scavenger Trait
There are two ways of finding Scavenger. The first and simplest, is unlocking it by collectively picking up 10,000 scrap.
The second option to unlock Scavenger, which may be faster but is a bit luck based, is keeping an eye out for the Tarnished Ring item while traveling through Earth. You will see it laying next to a skeleton like the purple glowing jewelry or the blue glowing Tomes of Knowledge, except this will have the orange glow associated with quest items. Once you have the ring, find Reggie back in Ward 13, and give him the ring. You may need to exhaust his question dialog options first.