Paper Flying Machine Kit
Source: Vendor.
The 
Paper Flying Machine Kit is a permanent toy obtained by redeeming a loot code from the Paper Airplane card found in the World of Warcraft TCG expansion March of the Legion, or by purchasing it from the Black Market Auction House.
Guide awaiting review
Obtain the TCG Loot Code
The Paper Flying Machine Kit comes from the Paper Airplane loot card in the March of the Legion TCG expansion, with a drop rate of approximately 1 in 121 booster packs. Sealed booster boxes contain 24 packs, making the average cost of pulling the card around $303 USD — purchasing a loose loot code on sites like eBay is far cheaper, with Buy It Now prices ranging from around $20 to $32 USD.
Try the Black Market Auction House
Landro Longshot occasionally lists the Paper Flying Machine Kit on the Black Market Auction House, with a starting bid of 
15,000 Gold — expect the final price to climb significantly higher from there. The following items also appear on the Black Market Auction House alongside it: 
Imp in a Ball, 
Dragon Kite, 
Fishing Chair, 
Goblin Gumbo Kettle, 
Hippogryph Hatchling, 
Picnic Basket, 
Tabard of Flame, 
Goblin Weather Machine - Prototype 01-B, 
Banana Charm, 
X-51 Nether-Rocket X-TREME, and 
Riding Turtle.
Tips
The toy itself is permanent, but the paper copters you create with it only last 30 minutes each.
