Yep, Tome of the Tranquil Mind. The consumable that you have to use when you want to swap specs. Without it, you have to be somewhere in a rested XP area (city, inn) to make the change. A beneficial item to have for raiding, running dungeons, or hell even for questing.

According to The Undermine Journal, these things sell on the AH for roughly 200g each. Your mileage may vary of course, but as of right now the average price is 200g. Other than the handful you get when you complete the New Dalaran quest at the start of the Legion expansion, the only other way to get them is to buy them off the AH or have a character with Inscription that can make them.

So what does this have to do with making gold with Class Trial characters? Allow me to explain:

• Create a new character, and select Class Trial. You’ll start with a fresh (temporary) level 100 character.
• After running through the brief tutorial, you will be sent to the Broken Shore scenario. Once there, leave the instance.
• You will appear in front of a quest-giver who tries to give you the option to enter the scenario. There’s also an option to skip the instance, which results in you being sent directly to New Dalaran.
• Once you spawn in New Dalaran, hand in your quest to the dude in front of you. He will reward you with the Dalaran Hearthstone and five Tomes of the Tranquil Mind.
• Go to the mailbox, mail the Tomes to a bank alt or another character. Log off, delete the character, rinse and repeat.

With this method, you can either load up with stacks of Tomes for free, or sell them on the AH. That’s roughly 1000g on the AH for maybe ten minutes of work.

Not too shabby, and oh so sneaky.