I had this prepared so will put this here, supports the 310 sale, adds some more.

Also mods told me to wait on MP.TF buyers to see if they'd sell seeing as they are both lower than the 310 sale.

Sale #1 -

Sold for Clairvoyance Lucky Cat Hat - Trade looks incompete, Lucky cat listed at 2000 $ on mp.tf or G.Pan here

https://backpack.tf/profiles/76561198039148402#!/compare/1543190400/1544140800

https://backpack.tf/profiles/76561198282372085#!/compare/1544054400/1544140800

Sale #2 -

Sold for duped Stormy 13th Hour Backwards Ballcap + Nebula Phononaut

https://backpack.tf/profiles/76561198019444465#!/compare/1541116800/1541203200

https://backpack.tf/profiles/76561198113188320#!/compare/1541116800/1541203200

Mini for duo-

Sold for duped Burning Flames Troublemaker's Tossle Cap + 192 keys

https://backpack.tf/profiles/76561198113188320#!/compare/1541116800/1541203200

https://backpack.tf/profiles/76561198182213262#!/compare/1541116800/1541203200

Mini for the Tossle Cap - Credit to Shuffle Spy:

https://backpack.tf/profiles/76561198179707937#!/compare/1541116800/1541289600 - Sold for a Disco Beat Down Hong Kong Cone

https://backpack.tf/profiles/76561198100050147#!/compare/1543968000/1544054400 - Bulk sale for a Cloudy Moon Patriot Peak

https://backpack.tf/profiles/76561198328624791#!/compare/1543881600/1544054400 - Bulk sale for a Harvest Moon Pyromancer's Mask

https://backpack.tf/profiles/76561198054862332#!/compare/1544400000/1544572800 - Bulk sale for a Harvest Moon Team Captain

https://backpack.tf/profiles/76561198232041512#!/compare/1545436800/1545523200 - Sold for 110 Keys

https://imgur.com/a/IiCT9hp - Supreme confirming his purchase, since the above compare link shows 109 Keys.

https://backpack.tf/profiles/76561198099481645#!/compare/1540857600/1541203200 - Sold + ~20 Keys of Items for a Sunbeams Ballcap

https://backpack.tf/profiles/76561198113188320#!/compare/1541116800/1541203200 - Bulk sale

https://backpack.tf/profiles/76561198061779536#!/compare/1541289600/1541376000 - Sold for a Burning Flames Field Practice + 7 Keys

https://backpack.tf/profiles/76561198061440669#!/compare/1542412800/1542499200 - Sold for 124 Keys

Already used for the Ballcap and the Field Practice suggestions.

Going with 117 for the Tossle.

117+192= 309 keys.

Mini for Duped Stormy 13th Hour Backwards Ballcap -

Sold for 145 keys

https://backpack.tf/profiles/76561198182213262#!/compare/1542240000/1542326400

Mini for Nebula Phononaut -

https://backpack.tf/profiles/76561197970361626#!/compare/1545696000/1545955200 - Sold for 168 keys

https://backpack.tf/profiles/76561198125071052#!/compare/1545955200/1546041600 - Sold with Strange Professional Killstreak Australium Sniper Rifle (36) for Nebula Universal Translator (185) + 6 keys

https://marketplace.tf/items/30647;5;u99 - Sold for 292.9 $ on November 3 - Keys at 1.78 - $292.9 / $1.78 = 164.55 keys

145+166= 311

Final price 310 keys

Sale #3-

Untrace -

https://backpack.tf/profiles/76561198070548996#!/compare/1540857600/1541116800

https://backpack.tf/profiles/76561198070018257#!/compare/1538006400/1541116800

Sale #4 -

Sold with Spirit of Halloween (Factory new Warpaint) for Green Energy Killer Exclusive

https://backpack.tf/profiles/76561198190084707#!/compare/1542585600/1543017600

https://backpack.tf/profiles/76561198070018257#!/compare/1542931200/1543017600

Mini for Green Energy Killer Exclusive

https://backpack.tf/profiles/76561198096247397#!/compare/1541203200/1541548800 -Sold for 190 keys + Burning Flames Modest Pile of Hat (187) + Holy Grail Taunt: The Balloonibouncer(~6.5 couldn't find a pure sale within 1 month) + 9 keys of sweets

190+187+6.5+9= 392.5

Final price 390 keys

Sale #5-

Sold for 200 keys

https://backpack.tf/profiles/76561198190084707#!/compare/1545523200/1545782400

https://backpack.tf/profiles/76561198061779536#!/compare/1545868800/1546041600

Sale #6 -

Sold for 405$ on mp.tf

https://marketplace.tf/items/538;5;u10/

Keys were 1.79$ https://manic.tf/keyprice/?at=2018-10-30

$405 / $1.79 = 226.26 keys

Sales at 200/226/310/390