Thundering Fury.

http://backpack.tf/item/5194620414

Sale 1) Sold for a Time Warp Cold Killer (68 Keys) + Power Surge Master's Yellow Belt (50 Keys) + ~13 Keys in Items

http://backpack.tf/profiles/76561198022933439#!/compare/1478563200/1478736000

68 + 50 + 13 = 131 Keys, which I'll round to 130 Keys

http://backpack.tf/item/5192309032

Sale 2) Sold for a Starstorm Slumber Deep Cover Operator (53.5 Keys) + Duped Haunted Ghosts Defiant Spartan (36 Keys) + ~20 Keys in Items + 10 Keys

http://backpack.tf/profiles/76561198040475618#!/compare/1477785600/1477958400

53.5 + 36 + 20 + 10 = 119.5, which rounds to 120 Keys

Deep Mini

http://backpack.tf/profiles/76561198150600884#!/compare/1479427200/1479513600 - Sold for a Burning Topi (40) + 1 Key + ~1 Key in Items

http://backpack.tf/profiles/76561198008113369#!/compare/1477699200/1477785600 - Sold for a Smoking Pyromancer's Mask

http://imgur.com/a/D2n6q - Sellers at 65 Keys and 68 Keys

Averaging 42 - 65 and using 53.5 Keys

Spartan Mini

http://backpack.tf/profiles/76561198138584731#!/compare/1476489600/1476576000 - Sold for a Logo Mirror + G. Fetti Softcap (15 Keys) + 5 Keys + ~2 keys in Items

http://www.tf2outpost.com/trade/28494325 - Capped by the Buyout of 36 Keys, as I doubt the Mirror is less than 14.