Instant Respawn Farm, Drops 13K Gold Item (Patreon)

In Elwynn Forest at 48.2, 87.6 is a small hut with a goblin Dockmaster inside. When you aggro the Dockmaster, three bodyguards appear. They only spawn when you aggro the Dockmaster. When you kill the bodyguards and drop combat with the Dockmaster you can repeat the process. 

Dropping combat for most classes is awkward and slow. However, because this is an open world location you can just use a hunter class trial, as hunters can drop combat quickly with feign death. 

Feign death has a 30 second cooldown, to increase the speed of the process you can go to either Mardan Thunderhoof in Sholazar Basin:

https://www.wowhead.com/npc=28040/mardan-thunderhoof

or Outfitter Reynolds in Trueshot Lodge in the Broken Isles 

https://www.wowhead.com/npc=103693/outfitter-reynolds

(note BFA quests seem to be interfering with the phasing that allows class trials to access legion content)

From these vendors buy the item "Pet Training Manual: Play Dead". 

This item allows you increase your farming speed by 100%, by allowing your pet to effectively feign death on a separate cooldown from the hunter's own feign death. 

Simply aggro the dockmaster, kill the bodyguards then feign death, then aggro the dockmaster with your pet, kill the bodyguards with your pet, then use play dead, come out of feign death and repeat the entire process.

The bodyguards drop the item "Burnt Leather Vest" which sells for an average of just under 13,000 gold across all realms. The drop chance is 1.2% which is by far the best source for this item given the speed of the instant respawn method.

I have not been able to find any mention of this farming technique on even the most obscure gold farming sites and channels so you (and possibly any other patreons on your realm) will have a complete monopoly on this item. I would avoid selling the item in the unlikely event there is one on the auction house already, and I would charge rather more than the average price (say 20K) because of the monopoly you have-buyers for this type of item are not price-sensitive. 

Items like this do not always sell quickly-however posting a number of rare and valuable items continuously like this is a very effective way to make gold. 

Additionally, the mobs do drop some interesting transmog gear with an average value in the range of 200-2,500 gold , much of it "imbued" items. If you have space in your inventory it isn't a bad idea to try and sell this stuff, obviously some people are buying it or the average price would be lower. However, I would treat it like an added bonus rather than something to farm for specifically. If you do try and sell it try and post the better part of a set of items as the chance of one buyer purchasing all items at once will be higher.