If one is attempting to use Alterac Valley as a way to increase your rep for any of the Horde factions, then doing the repeatable turn in quests like this one are a must.
This particular quest leads into the "More Booty!" repeatable version. The rep reward for that is 10 rep with Orgrimmar per 20 armor scraps turned in. This might not seem like a lot of rep at first, but keep in mind that armor scraps are some of the most abundant drops off of your fallen enemies, often dropping ~20 armor scraps apiece. If you are constantly in the heat of battle and remember to loot the ones who are killed, you can quite easily pick up several hundred armor scraps to turn in.
Additionally, turning in numerous stacks of armor scraps to Smith Regzar will allow him to upgrade the guards that protect your territory and graveyards from veterans to champions all the way to elite. Turning in armor scraps also will reward you with a 30 minute "Polished armor" buff that increases your armor by 10%
One last thing to remember. Getting "Orgrimmar" rep from any of these quests also gives rep across the faction board, so if you are looking to get to exalted with everyone in the faction, Alterac Valley is your most cost-and-time effective option as opposed to buying/farming runecloth and turning them in at 75 rep/stack of 20
Tonight while AVing off and on over a four hour period netted an increase of 1200 points of rep from this and the other repeatable turn ins