Hotshot.

https://backpack.tf/item/954984269

Sale 1) Sold for 125 Keys

https://backpack.tf/profiles/76561198025963071#!/compare/1544832000/1544918400

Sale 2) ?

https://backpack.tf/profiles/76561198046921199#!/compare/1545350400/1545436800

https://backpack.tf/profiles/76561198102195119#!/compare/1544659200/1545436800

https://backpack.tf/item/288120197

Sale 3) Sold for $224.88 when Keys were ~$1.73 each

https://marketplace.tf/items/150;5;u13

https://marketplace.tf/items/5021;6/Mann%20Co.%20Supply%20Crate%20Key

224.88 / 1.73 = 129.99, which rounds to 130 Keys

Sale 4) Sold + Tesla Coil Pestering Jester (which instantly resold for 21 Keys + 1 Refined) + Screaming Tiger Fresh Brewed for a Scorching Dapper's

https://backpack.tf/profiles/76561198075991823#!/compare/1545955200/1546041600 - Buyer's Backpack

https://backpack.tf/item/5226196545 - The Jester

Supports the low end.

Dapper Mini

https://backpack.tf/profiles/76561197996306396#!/compare/1551484800/1551571200 - Sold for 140 Keys

https://backpack.tf/profiles/76561198832253171#!/compare/1551571200/1551830400 - Sold for something around 145 Keys

https://backpack.tf/item/277398724

Sale 5) ?

https://backpack.tf/profiles/76561198041374163#!/compare/1544572800/1544832000 - Seller's Backpack

https://backpack.tf/profiles/76561198799922000#!/compare/1545696000/1545782400 - Buyer's Backpack

https://backpack.tf/item/492870467

Sale 6) Sold for a Tesla Coil Killer Exclusive (76 Keys) + Morning Glory Familiar Fez (37 Keys) + Smoking Exquisite Rack (39 Keys) + ~14 Keys of Items

https://backpack.tf/profiles/76561198081270783#!/compare/1540771200/1540857600

76 + 37 + 39 + 14 = 166, which I'll round to 165 Keys

Killer Exclusive Mini

https://backpack.tf/profiles/76561198081270783#!/compare/1541289600/1541376000 - Sold for a Haunted Ghosts Hat With No Name (61 Keys) + 6 Keys

https://backpack.tf/profiles/76561198310127340#!/compare/1544918400/1545004800 - Sold for a Sunbeams Brigade Helm (79 Keys) + 6 Keys

https://backpack.tf/profiles/76561198446905869#!/compare/1546300800/1546387200 - Sold for either 77 or 78 Keys (was listed at 77 Keys)

https://imgur.com/a/bJuFlyY - Proof the above sale was listed at 37 Keys.

Taking 67 - 85

HWNN Micro

https://backpack.tf/profiles/76561198080179568#!/compare/1547769600/1547856000 - 52 to a buy order

https://backpack.tf/profiles/76561198002757046#!/compare/1549670400/1549756800 - Most likely 58 Keys

https://imgur.com/a/WWowGti - The 58 Key Buyout

https://backpack.tf/profiles/76561198006544512#!/compare/1551830400/1551916800 - 99% sure it's 61 Keys

https://imgur.com/a/bYKgCJD - Was listed for 61 Keys

https://backpack.tf/profiles/76561198049673314#!/compare/1551225600/1551571200 - Think it may have been 63 Keys

https://imgur.com/a/aOldF56 - Was listed for 64 Keys. Don't know why the Buyer would pay 64 when there was another Seller at 63 Keys.

Taking 58 - 64 Keys

Brigade Micro

https://backpack.tf/profiles/76561197980749062#!/compare/1547251200/1547337600 - Sold for 73 Keys + ~6 Keys of Items

Taking 79 Keys

Using these old sales because this suggestion would've been fine when I made this just over 2 months ago.