The most simple thing is TradeSkillMaster. This AddOn shows you quite an amount of information in the items tooltip. In my opinion, DBRegionMarketAvg the best source. It tells me the price, an item was posted on all EU realms in the last 14 days. Why not DBMarket? DBMarket only shows you the items value from your server in the last 14 days. This value often gets manipulated. Some people start to post an item with a 500g value for 500.000 Gold on the auction house for several weaks. As a consequence, DBMarket is rising towards 500.000 Gold.  If you use DBMarket with 100% and post your item for 500.000 Gold, nobody will buy it.
And if you decide you need to go back to an early zone to get low level minerals or herbs? Instead of meekly wandering around ignoring you to gather in peace, now the local mobs are the same as you again and aggro on you. So you have to fight your way in and out. Same spell rotation, over and over and over. 31373433. 31373433. 31373433. 31373433. 31373433. 31373433. Every combat the same. Over and over again. Never ending. No change. Mind numbing. No challenge.
I used Zygor for legion and BFA, used AA on an alt for BFA. Personally i like Zygors format more. I like being able to target things like achievements. I used Zygor to get my Mindworm and my Lucid Nightmare as well as finish the Rep grinds for the allied races. I have zero complaints. My experience was great. I also used Zygor for some professions, recipe acquisition, a couple mounts, all of the Suramar quest line. Thank God for that. And for the last zone of Draenor on my Demon Hunter.. i forget the name.. Whatever the big daily hub thing was called.

Allied races are variants of existing races. The Void Elves are a version of Night Elves, while the Highmount Tauren are, you guessed it, a version of the Tauren. Four allied races are already in the game before launch and two more, the Dark Iron Dwarves and Mag’har Orcs, were added after Battle for Azeroth launched. Each Allied Race has its own racial abilities. You can also unlock a heritage armor set by leveling any Allied Race to the level cap.