While not really Legion related (just seems silly bumping the WoD topic when no one really cares about that expansion anymore), if anyone wants some extra money you can do the Children's Week pet quests -> choose the Pet Care Package reward from them -> sell Flawless Battle-Stones for 3-5k+ each on the Auction House. This price will probably drop during this event if more people notice and do this but will probably go back up after Children's Week ends. You can get 3 per character if you do the Stormwind/Orgrimmar, Shatt, and Dalaran quests.
edit: Think you need the pets from the Dalaran quest already to have the option to get the Pet Care Package though.
edit 2: Event ended today.