Most of this was copied from the suggestion by Bird Can't Count but taking into account the most recent sale

https://backpack.tf/item/3128789548

Sale 1:

https://imgur.com/a/ZjVS74Q

https://backpack.tf/profiles/76561198184172198#!/compare/1628553600/1628640000

https://backpack.tf/profiles/76561198410760897#!/compare/1628553600/1628640000

Sold for MG Belgian Detective + Amatharamine Flipped Trillby + 40 pure

Sale 2:

https://backpack.tf/profiles/76561198022071751#!/compare/1620604800/1620777600

https://backpack.tf/profiles/76561198209640976#!/compare/1620691200/1620777600

260 keys

Sale 3:

https://backpack.tf/profiles/76561198406114836#!/compare/1621900800/1621987200

https://backpack.tf/profiles/76561198209640976#!/compare/1621900800/1621987200

Bulk sale

Sale 4:

https://backpack.tf/profiles/76561198406114836#!/compare/1622505600/1622592000

https://backpack.tf/profiles/76561198258937500#!/compare/1622505600/1622592000

Bulk for Spec KS Chiroptera Venenata Killer's Kabuto

Sale 5:

https://backpack.tf/profiles/76561198258937500#!/compare/1625788800/1625875200

https://backpack.tf/profiles/76561198155066949#!/compare/1625788800/1625875200

1:1 for a Sunbeams Whirly Warrior

Sale 6:

https://backpack.tf/profiles/76561198155066949#!/compare/1625961600/1626048000

https://backpack.tf/profiles/76561198058323007#!/compare/1625961600/1626048000

Massive bulk w/ keys for PS Blast defense as per https://backpack.tf/suggestion/60f360ba19ee0034e262fd64

Sale 7:

https://backpack.tf/profiles/76561198058323007#!/compare/1626307200/1626393600

https://backpack.tf/profiles/76561198846276257#!/compare/1626307200/1626393600

300 keys

Mini for sunbeams whirly warrior not possible: https://backpack.tf/item/7956778593

Only sale was the 1:1 for ooze mohawk

This should be from at least 70+252+40 (suggested values of the most recent hats in question) = 362 to 100+350+40 (listing prices) = 490.

I'm also fairly new to suggesting, so if there are any problems with this suggestion please do tell me.