Sale 4 wasn't for the stuff you listed, it was for a Misty Liq Lid + 4 keys in adds, which apparently was bought for the Geezer + taunt + sweets.

https://backpack.tf/profiles/76561198121830870#!/compare/1521244800/1521331200

The B/O you listed doesn't belong to that sale either. You also missed other sales:

Buyer from above resold for a taunt (sellers at 25-35, would need a proper mini but it's certainly much lower than the above sale)

https://backpack.tf/profiles/76561198114545227#!/compare/1521504000/1521590400

https://backpack.tf/profiles/76561198036270946#!/compare/1521590400/1521676800

36 keys (IDs match)

https://backpack.tf/profiles/76561198114545227#!/compare/1521936000/1522022400

https://backpack.tf/profiles/76561198081937913#!/compare/1521936000/1522022400

GBH Larrikin + (at least) 12 keys in sweets

https://backpack.tf/profiles/76561198079861152#!/compare/1522195200/1522627200

https://backpack.tf/profiles/76561198081937913#!/compare/1522108800/1522195200

Bulk for Blizzardy BOA

https://backpack.tf/profiles/76561198079861152#!/compare/1522195200/1522627200

https://backpack.tf/profiles/76561198153417214#!/compare/1522454400/1522627200

So you have sales at 33 (close to buyers), 36, 37, 45+ (resold for less than 35), 60+. Honestly I would go with 36-37 here.