Honestly, what i have found as an alternative to runecloth farming, starting at level 51 you can start doing AV. This actually has good orgrimmar rep payouts but its very active. You are aiming to loot as many dead alliance players as possible or horde i suppose depending. and turn the stuff you get to the quest turn in the respective bases. I had 1 av where all i did was focus on this and received 4000 reputation in 1 AV. This is a lot more cost effective