Boo

SALE 1

Massive bulk sale

https://backpack.tf/profiles/76561198069618862#!/compare/1512518400/1560211200

https://backpack.tf/profiles/76561198064982470#!/compare/1559865600/1560211200

SALE 2

Sold for 40 keys

https://backpack.tf/profiles/76561198064982470#!/compare/1564704000/1564790400

https://backpack.tf/profiles/76561198279539667#!/compare/1564704000/1564790400

B/o was 42 keys

https://bot.tf/stats/listings/4W6XPONX

SALE 3

Unknown

https://backpack.tf/profiles/76561198279539667#!/compare/1564790400/1564876800

https://backpack.tf/profiles/76561198010993339#!/compare/1564790400/1564876800

SALE 4

Unknown

https://backpack.tf/profiles/76561198287198615#!/compare/1564790400/1564876800

SALE 5

Unknown -though i think this one is the mp sale

https://backpack.tf/profiles/76561198012428488#!/compare/1560902400/1561075200

https://backpack.tf/profiles/76561198086948995#!/compare/1560988800/1561075200

B/o was also 70 keys

https://bot.tf/stats/listings/Y92EVZW4

SALE 6

Sold for 50 keys + 17 refined

https://backpack.tf/profiles/76561198311498888#!/compare/1558915200/1559001600

https://backpack.tf/profiles/76561198121991829#!/compare/1558828800/1559001600

Rounds down to 50 keys

SALE 7

Unknown

https://backpack.tf/profiles/76561198121991829#!/compare/1559520000/1559779200

https://backpack.tf/profiles/76561198832602199#!/compare/1559692800/1559779200

SALE 8

Unknown

https://backpack.tf/profiles/76561198832602199#!/compare/1564012800/1564099200

https://backpack.tf/profiles/76561198126114757#!/compare/1564012800/1564099200

SALE 9

Sold for 42 keys

https://backpack.tf/profiles/76561198126114757#!/compare/1564012800/1564099200

https://backpack.tf/profiles/76561198079764636#!/compare/1562630400/1564185600

MARKETPLACE SALE

129.5 on june 21 (129.5 / 1.84 = 70.38 rounding to 70 keys)

https://marketplace.tf/items/tf2/148;5;u14

CLASSIFIEDS

https://gyazo.com/ad36020b4c1c9ceb58b0de2ac2b37c76

Sales at 40, 42, and 50. Marketplace sale at 70. Seller at 49.

Safe to say 70 is quite high, taking 40-50 keys.