For this farm we're taking it all the way back to eastern kingdoms. We're going to be killing the purespring elementals in the purespring cavern for the item essence of water. Essence of water is a semi-rare drop that goes for a shocking 252g per piece. The caveat is that it doesn't drop all too often, but is still worth the trouble. I wasn't getting TOO many of these, but I was still making bank with them. The essences are used to create the old-world illusions, so they do have some inherent value. Simply patrol the area and kill as many elementals as your heart desires. It's a really cool and fun farm that can be done on autopilot. Usually there is noone patrolling the spot.
Vigilance Perch is essentially an automatic mount when out of combat. Despite its tooltip, it only allows you to fly in flying zones, so you will not be able to fly in Battle for Azeroth zones. This is a great Legendary to pair up with Sephuz's Secret. Choosing between this and Apex will come down to personal preference and how you prefer to level. When speed-leveling with consumables, you will not get full value out of the mount ability of this Legendary. If you are just leveling normally, try them both out and see what works best for you.
I personally wouldn't recommend Bloodmyst Isle. There's a ton of quests but a lot of those quests have absolutely horrible drop rates on their items. A lot of the quest mobs also have very slow and/or spread out spawns so if there's other people there you're gonna be waiting for respawns or spending a lot of time traveling between spawn areas quite a bit. Overall it's just an incredibly slow zone as far as EXP goes.
Guide to Obtaining and Selling the WoW Token Buying and selling the WoW Token, which allows players to buy game time with gold, or make extra gold by selling the token on the Auction House. What is Blizzard (Battle.net) Balance Overview of Blizzard (Battle.net) Balance, a currency used to buy Blizzard Entertainment products including World of Warcraft character services. How to Purchase World of Warcraft Game Time The cost of a WoW game time subscription, how to acquire a subscription, gift one, and cancel it, as well as how to play WoW for free.