Sale 1:

Sold for Miami Nights Halogen Head Lamp (Suggestion at 15) + 5 keys

http://www.tf2outpost.com/trade/29490871 - No visible B/O

Seller: https://backpack.tf/profiles/76561198159855421#!/compare/1514419200/1514505600

Buyer: https://backpack.tf/profiles/76561198146505878#!/compare/1514419200/1514505600

X = 20

Sale 2:

Sold for 16 keys

Seller: https://backpack.tf/profiles/76561198346669763#!/compare/1512086400/1512172800

Buyer: https://backpack.tf/profiles/76561198003946713#!/compare/1512086400/1514246400

X = 16

Sale 3:

Bulk for bulk

Seller: https://backpack.tf/profiles/76561198011321852#!/compare/1512172800/1512259200

Buyer: https://backpack.tf/profiles/76561198238677960#!/compare/1510790400/1512259200

Sale 4:

Bulk for Terror-Watt Le Party Phantom

Seller: https://backpack.tf/profiles/76561198042254681#!/compare/1511308800/1512604800

Buyer: https://backpack.tf/profiles/76561198024925599#!/compare/1511222400/1511308800

Sale 5:

Bulk for stuff

Seller: https://backpack.tf/profiles/76561198024925599#!/compare/1511913600/1512000000

Buyer: https://backpack.tf/profiles/76561198013245606#!/compare/1511740800/1512000000

Sale 6:

Quicksold for some amount of keys

Seller: https://backpack.tf/profiles/76561198013245606#!/compare/1512000000/1512086400

Buyer: https://backpack.tf/profiles/76561198346669763#!/compare/1511913600/1512086400

Sale 7:

Bulk for Beams Tyrants

Seller: https://backpack.tf/profiles/76561198003946713#!/compare/1514678400/1514764800

Buyer: https://backpack.tf/profiles/76561198066195760#!/compare/1514678400/1514764800

Miami Nights Halogen Headlamp:

https://backpack.tf/suggestion/5a509456cf6c754e381d7ee4

Sellers:

16 keys:

https://i.imgur.com/AxQY1C9.png - young

17 keys:

https://i.imgur.com/xBdWGXb.png - 5 days

20 keys:

https://i.imgur.com/bnDmcZM.png - 13 days

Sales at:

16

20

Going with 16-20.