Sellers:

https://marketplace.tf/items/137;5;u6

https://backpack.tf/item/1921857510 - b/o: $53 = 26 keys / 24 keys (9 days)

http://imgur.com/a/AGKrk - b/o: 18 keys (3 days)

Sold:

https://backpack.tf/profiles/76561198190577279#!/compare/1497830400/1497916800

https://backpack.tf/profiles/76561197963500354#!/compare/1497830400/1497916800 - ?

https://backpack.tf/profiles/76561198190577279#!/compare/1497744000/1497830400 - bulk

https://backpack.tf/profiles/76561198071197720#!/compare/1497744000/1497830400 - bulk

https://backpack.tf/profiles/76561198146080783#!/compare/1497571200/1497744000 - sold for Disco Beat Down Dead Cone (16) + Aces High Virtual Reality Headset (12) = 28 keys

http://www.tf2outpost.com/trade/29210220

https://backpack.tf/profiles/76561198129088942#!/compare/1497398400/1497571200 - sold for 20 keys

https://backpack.tf/profiles/76561198086348188#!/compare/1497744000/1497830400 - sold for Kill-a-Watt Ye Oiled Baker Boy (15) + 7 keys + sweets (1) = 23 keys

https://backpack.tf/profiles/76561197963500354#!/compare/1499731200/1499817600

https://backpack.tf/profiles/76561198101622055#!/compare/1499644800/1499990400 - sold for 17 keys

Credits to Jarool

Mini's:

Aces High Virtual Reality Headset:

https://backpack.tf/suggestion/595cc34acf6c7538bf6599d2 = 12 keys

Conclusion:

sales at 17, 20, 23, 28

taking 17-23 keys

Previous Suggestion: https://backpack.tf/suggestion/595cc53acf6c75413d2c9d98