Item 1: https://backpack.tf/item/16714868689

Sale 1:

buyer: https://backpack.tf/profiles/76561198177872379#!/compare/1769990400/1770249600

seller: https://backpack.tf/profiles/76561198273732193#!/compare/1770163200/1770249600

bp buy by Ender, went on mp bot right away

Sale 2:

https://imgur.com/a/jWLwspb

mp sale on Feb 19th 69.99 / 1.88 = 37

Item 2: https://backpack.tf/item/16727771404

buyer: https://backpack.tf/profiles/76561198333311272#!/compare/1770336000/1770422400

seller: https://backpack.tf/profiles/76561198282065071#!/compare/1770336000/1770422400

25 keys

Item 3: https://backpack.tf/item/16608106986

buyer: https://backpack.tf/profiles/76561198838586562#!/compare/1766707200/1766966400

seller: https://backpack.tf/profiles/76561197967159739#!/compare/1766620800/1766707200

only minigun matches but not keys, my best guess is it's 27 keys as those keys have no item history and the minigun sale was to a 'new' player who might've had a private profile and bought those keys from the ingame store so no history on them, either way it's within range

Item 4: https://backpack.tf/item/13587416891

Sale 1:

buyer: https://backpack.tf/profiles/76561198336662358#!/compare/1769040000/1769126400

seller: https://backpack.tf/profiles/76561198071082937#!/compare/1769040000/1769126400

1:1 for Treasure Trove Boston Brain Bucket, better used there as this is the only valid sale

Sale 2:

buyer: https://backpack.tf/profiles/76561199123301489#!/compare/1770076800/1770163200

seller: https://backpack.tf/profiles/76561198336662358#!/compare/1770076800/1770163200

1:1 for a genuine pro ks exorcism awper

Sale 3:

buyer: https://backpack.tf/profiles/76561198120672630#!/compare/1770336000/1770422400

seller: https://backpack.tf/profiles/76561199123301489#!/compare/1770336000/1770422400

Stormy Storm Liquidator's Lid + 1 key, using on the Lid as this is the only valid sale

Sale 4:

buyer: https://backpack.tf/profiles/76561199761274249#!/compare/1771372800/1771545600

seller: https://backpack.tf/profiles/76561198120672630#!/compare/1771459200/1771545600

Molten Mallard Bombing Run + 2 keys, better used on the B. Run

Sale 5:

buyer: https://backpack.tf/profiles/76561198047609644#!/compare/1771459200/1771545600

seller: https://backpack.tf/profiles/76561199761274249#!/compare/1771545600/1771718400

29 keys

Taking 25-37