Bubble Buddy

https://backpack.tf/item/5277967743

Sale 1) Sold for an Infernal Flames Meet the Medic + Green Confetti Cosa Nostra Cap

https://backpack.tf/profiles/76561198016070169#!/compare/1494288000/1494374400

http://www.tf2outpost.com/trade/28871558 - Capped by the Buyout of 42 Keys

Sale 2) Sold + ~14 Keys of Items for an Orbiting Fire Killer Exclusive (48.5 Keys)

https://backpack.tf/profiles/76561198318701679#!/compare/1494374400/1494460800 - Seller's Backpack

https://backpack.tf/profiles/76561198254377432#!/compare/1494374400/1494460800 - Buyer's Backpack

48.5 - 14 = 34.5, which rounds to 35 Keys

Killer Exclusive Mini

https://backpack.tf/suggestion/591e5b8a0e2cad52cd178148 - 48.5 Keys

Sale 3) Sold for a Stormy Storm Dr's Dapper Topper (39.5 Keys)

https://backpack.tf/profiles/76561198254377432#!/compare/1494460800/1494547200

Rounding to 40 Keys

Sale 4) Sold + Blizzardy Storm Whoopee Cap (15 Keys) for a Sunbeams Hotrod (46.5 Keys)

https://backpack.tf/profiles/76561198155841401#!/compare/1494547200/1494633600

46.5 - 15 = 31.5, which rounds to 32 Keys

Whoopee Mini

http://backpack.tf/suggestion/5921b4a80e2cad6773400c69 - 15 Keys

Hotrod Mini

https://backpack.tf/profiles/76561198080179568#!/compare/1490054400/1490140800 - Sold for a Green Confetti Team Captain + Max's Severed Head

http://www.tf2outpost.com/trade/28841085 - Capped by the Buyout of 48 Keys

https://backpack.tf/profiles/76561198239598834#!/compare/1490313600/1490918400 - Sold for a Circling Hearts Fancy Fedora (45 Keys)