Sky Golem for 10k Gold is a safe bet. Requires 30 Living Steel and every day 10 Ghost Iron Bar to make, no one in WOD cant be arsed to do that shit.
Royal Satchel - not a sure bet. In 6.0 daily cd is removed, we get the toy box, ressources now will stack up to 200, void storage gets a 2nd store unit (like guild bank), a guild bank now has a extra ressource store tab, 32 bags have been datamined for tailors, windwool cloth being used for enchant shuffel to get Spirit Dust (lvl Enchanting) - so yeah, not really a big investment when you consider this.
stock up on living steel since they are still required in all 4 jewelcrafter mounts + epic one, the sky golem, the 2 engineer pets. they are at 250g now at most realms so i expect the prices to rise rapidly if the Living Steel Alchemy Daily CD is on the same CD as the new Draenor Alchemy Transmute CD (like Truegold is now for Living Steel).