This NPC is located inside your [building=144] which requires [item=111986] to be learned and then selecting your [building=111] and clicking upgrade.
Once upgraded, you will find him laying on the floor with the spell [spell=29266] cast on him, and a yellow quest icon to pick up the quest.
This quest is an instant complete, meaning that you can't actually "accept" the quest. You complete the quest by gathering all of the required components either on the auction house, or by farming draenor mobs. From what I understand the parts required can drop from any mob in the draenor zone, and do not drop in their "completed" form.
The quest itself says the following :
"Auctioning For Parts"
The power crystal for this unit has been disconnected. Whatever did this also managed to rip out four of the other support modules.
If you found all of these items, you're confident you could restore it>
Super Cooling Module
Arcane Crystal Module
Auction Control Module
Universal Language Module
Cyclical Power Module
Following is the parts list for the above parts, and the spell that is cast when you "use" any of the items in the list after having a complete set.
Super Cooling Module
Casts: [spell=174521]
Auction Value
Arcane Crystal Module
Casts: [spell=174418]
Auction Value
Auction Control Module
Casts: [spell=174513]
Auction Value
Universal Language Module
Casts: [spell=174515]
Auction Value
Cyclical Power Module
Casts: [spell=174522]
Auction Value
The price to buy all of the components off the auction house at the time of writing this is approximately 50,000 - 60,000 gold, estimating the parts that have no prior listing at around 10,000 - 15,000 gold based on the price of the components that have been listed.
Arguably, this is likely the most sought after item in player garrisons, however it does require sacrificing one of your plots for a Trading Post, that is upgraded to at least level 2. Having at least a [building=144] is required to start collecting the parts as drops from mobs, and also grants the ability to buy various transmogrification items, toys, companions, as well as having the regular vendor which you can continue to exchange garrison supplies for crafting materials. You can also assign a Follower to this building which will help speed up the production rate when exchanging crafting mats for garrison supplies.
UPDATE: The price to buy these parts now is approximately 250,000 gold with the lowest priced item being the Auction Control Module ( under 200g ), and the most expensive part being the Universal Language Module ( median 150,000g ). I presume these prices are gauged based on the rarity and difficulty in obtaining some or all of the parts required to build those modules.