Always check each of the prices of the item, and look over a spread of several days. This is not so important on small items, but anything that you are spending hundreds of gold on you need to check prices carefully. It is also a good idea to check a website such as Allakhazam, Goblin Workshop, Wowhead or WoWuction to see what an item normally sells for.
Shadowfang is the twink dungeon. You can get a bunch of different valuable twink items here. When soloing at a high level though all items will be level 60, except for in chests. The items in the chests will be around level 20 and those are the ones with the most value. A level 20 Shadowfang will be worth several times what a level 60 one is worth. Bringing a Rogue or someone who can open locked chests is therefor advised.
Destructions Warlocks have also seen quite a few changes at the beginning of Battle for Azeroth. As they currently stand, they are a fairly safe pick for most types of encounters. While overall their damage output is average, their sustained damage abilities make them incredibly stable and adaptable in both single and multi-target encounters. They also have the lowest ramp up time of any Warlock spec, meaning they will be good to go from the start of a fight. They also feature highly customizable talent trees which produces a more flexible gameplay that can be shaped on a per-encounter basis.
**Players can repeat the Battle for Azeroth trial experience with up to 12 characters per qualifying account during the welcome back weekend. The Battle for Azeroth trial experience ends after three hours of game play in Battle for Azeroth, or after the quest "We Need Each Other" (for Horde) or "A Nation Divided" (for Alliance), whichever comes first.