Sincario

https://backpack.tf/item/2344337212

Sale 1) Sold for 69 Keys

https://backpack.tf/profiles/76561198085951237#!/compare/1522972800/1523059200

Low outlier.

https://backpack.tf/item/5106951372

Sale 2) Sold for ~83 Keys of Australiums + 3 Keys

https://backpack.tf/profiles/76561198024925599#!/compare/1525824000/1525910400

83 + 3 = 86 Keys

Sale 3) Sold for 70 Keys

https://backpack.tf/profiles/76561198425857649#!/compare/1529020800/1529107200

https://backpack.tf/item/6829394486

Sale 4) Sold for a Starstorm Slumber Hong Kong Cone

https://backpack.tf/profiles/76561198368868701#!/compare/1528243200/1528329600

Fits in the range.

Sale 5) Sold + 4 Keys for a Circling TF Logo Brown Bomber + Circling TF Logo Company Man + ~1 Key of Items

https://backpack.tf/profiles/76561198138684245#!/compare/1528156800/1528329600

http://www.tf2outpost.com/trade/29676901 - Capped by the Buyout of 90 Keys

Sale 6) Sold for 74 Keys

https://backpack.tf/profiles/76561198051813019#!/compare/1528243200/1528329600

https://backpack.tf/profiles/76561198071197720#!/compare/1528243200/1528329600

I asked Vertigo on Steam, and he said the sale was 74 Keys.

Sale 7) Sold + 40 Keys for a Bonzo-the-All-Gnawing Harmburg

https://backpack.tf/profiles/76561198071197720#!/compare/1528761600/1528848000

https://backpack.tf/profiles/76561198055847835#!/compare/1528761600/1528848000

Not all 40 Keys show, but I asked Lila on Discord. This should be used for the Harmburg.

https://backpack.tf/item/2496204444

Sale 8) Sold for 65 Keys

https://backpack.tf/profiles/76561198066802889#!/compare/1523232000/1523318400

Low outlier.

https://marketplace.tf/items/538;5;u61 - Sale at $159.09 when Keys were ~$1.96 at the time

159.09 / 1.96 = 81.16, which rounds to 81 Keys