Here’s a quick way to make some gold, which will be especially handy if you already have plenty of alts! Bosmer-Bussy noted the Algeth’ar Academy vendor item worth 2112 gold, located under the bronze dragon race, beneath a tree where a tauren is modeling for a dracthyr painter (at 60.2, 41.7). However, you’ll need to be level 64 to actually loot it, so whatever plans you may have had of rushing your alt army over there, you’ll have to get them a few levels first.
Some players are reporting not actually getting the brush, but around 500 gold instead, but only on some of their characters.