Yay. I have exactly 2000 accepted Unusual suggestions and exactly enough accepted total suggestions to be a Triple Black + Blue :D

https://backpack.tf/item/5075934487

Sale 1) Sold for 20 Keys to a quickbuyer

https://backpack.tf/profiles/76561198114442177#!/compare/1539734400/1539907200

Sale 2) Sold for 20 Keys + ~3 Keys of Items

https://backpack.tf/profiles/76561198024867201#!/compare/1542326400/1542412800 - Seller's Backpack

https://backpack.tf/profiles/76561198168246671#!/compare/1542326400/1542412800 - Buyer's Backpack

https://backpack.tf/profiles/76561198119936533#!/compare/1542326400/1542412800 - The Stove Pipe first sold for 20 Keys.

20 + 3 = 23 Keys

https://backpack.tf/item/6304330170

Sale 3) Either some amount of Keys between 23 and 28, a Pro KS Aussie Knife (26 Keys), or 2 Stranges worth 29 Keys

https://backpack.tf/profiles/76561197992322606#!/compare/1536019200/1536105600 - Bomber Seller, got the Stranges from Person 4

https://backpack.tf/profiles/76561198296497176#!/compare/1536019200/1536105600 - Bomber Buyer, sold the Knife to Person 3

https://backpack.tf/profiles/76561198148148506#!/compare/1535846400/1536192000 - Person 3, bought the Knife for some number of Keys

https://backpack.tf/profiles/76561198015281106#!/compare/1536019200/1536105600 - Person 4, got the Keys from Person 1 and sold the Stranges

Sale 4) Sold for 23 Keys

https://backpack.tf/profiles/76561198296497176#!/compare/1536105600/1536192000

https://backpack.tf/profiles/76561198287940798#!/compare/1536105600/1536192000

Sale 5) Sold for an Australium Sniper Rifle (~22 Keys at the time) + 4 Keys

https://backpack.tf/profiles/76561198287940798#!/compare/1536624000/1536710400

22 + 4 = 26 Keys

Sale 6) Sold + ~1 Key of Items for a Terror-Watt Whirly Warrior + Aces High Bonk Helm

https://backpack.tf/profiles/76561198100103299#!/compare/1538265600/1538438400

https://backpack.tf/profiles/76561198364475021#!/compare/1538352000/1538438400

High outlier.

Sale 7) Bulk sale for a Green Energy Neckwear Headwear

https://backpack.tf/profiles/76561198143969056#!/compare/1538956800/1539043200

Sale 8) Sold to a quickbuyer for 22 Keys

https://backpack.tf/profiles/76561198215559840#!/compare/1539475200/1539561600

Sale 9) Sold for ? Keys

https://backpack.tf/profiles/76561198002757046#!/compare/1541030400/1541116800

https://backpack.tf/profiles/76561198197708585#!/compare/1541030400/1541116800

Sale 10) ?

https://backpack.tf/profiles/76561198197708585#!/compare/1541116800/1541289600

https://backpack.tf/item/3042253334

Sale 11) Sold to a quickbuyer for 21 Keys

https://backpack.tf/profiles/76561198147726750#!/compare/1538697600/1539216000

Sale 12) ?

https://backpack.tf/profiles/76561198337734785#!/compare/1542153600/1542240000

https://backpack.tf/profiles/76561198046178525#!/compare/1542153600/1542240000

https://imgur.com/a/Ne3AL4C - 9 Day Seller at 23 Keys, 8 Day Seller at 25 Keys, and a 9 Day Seller at 25 Keys

https://backpack.tf/item/6304330170

https://backpack.tf/item/3042253334

https://backpack.tf/item/1323972230