Thanks to Icycrevasse for helping out!

Item 1

https://backpack.tf/item/386759122

Sale #1

Sold for 21 keys-

Seller: https://backpack.tf/profiles/76561198224551028#!/compare/1682035200/1683676800

Buyer: https://backpack.tf/profiles/76561199192088525#!/compare/1683590400/1683676800

Sale #2

Untraceable-

Seller: https://backpack.tf/profiles/76561199192088525#!/compare/1683590400/1683676800

Buyer: https://backpack.tf/profiles/76561198032176942#!/compare/1683590400/1683676800

Item 2

https://backpack.tf/item/9720685103

Sale #3

Sold a Strange Festivized Australium Medi Gun (42 keys, many sales have happened around the $80-100 mark, the range ending up at about 38-45)-

Seller: https://backpack.tf/profiles/76561198444581710#!/compare/1682294400/1682467200

Buyer: https://backpack.tf/profiles/76561198057839982#!/compare/1682035200/1682294400

Market Sales

Sale #4

Seems to have sold for 18 keys but maybe something is missing, unusable-

Seller: https://backpack.tf/profiles/76561198057839982#!/compare/1682294400/1682812800

Buyer: https://backpack.tf/profiles/76561199244599385#!/compare/1682294400/1682467200

Sale #5

Sold for 31 keys-

Seller: https://backpack.tf/profiles/76561199244599385#!/compare/1682553600/1682640000

Buyer: https://backpack.tf/profiles/76561199426345594#!/compare/1682640000/1682726400

Sale #6

Untraceable-

Seller: https://backpack.tf/profiles/76561199426345594#!/compare/1682812800/1682899200

Buyer: https://backpack.tf/profiles/76561198073168400#!/compare/1682899200/1684454400

Item 3

https://backpack.tf/item/264340549

Sale #7

Bulk transfer-

Seller: https://backpack.tf/profiles/76561199102777012#!/compare/1686700800/1686787200

Buyer: https://backpack.tf/profiles/76561197980309466#!/compare/1683763200/1686787200

Sales @ 31, 42

Taking 31-42 as a conservative drop