I also would like to add that we do not have any guides for transmogrify items other than Allied Races, and the new Shadowlands Allied Race Gear from their added quest-lines.
There are vendor guides but we have not continued them because the game has changed in a very big way since then. Gold is easier to make now.
You can easily make a new character and level it to 60. You would have over 10k gold if you don’t spend too much gold. That’s mostly quest rewards, selling items you get from mobs and quests. If you utilize TSM 4.0 with appraiser, you can make even more gold. There are guides on Youtube that teach you how to use TSM 4.0.
A few times I wanted to make guides for transmog, hunter pets, gold making etc. It’s just a nightmare to make and maintain whenever Blizzard makes changes.