Credit to A Delicious Cashew for the proof

Ancient Eldritch Hellmet

https://backpack.tf/item/9921801920

https://gladiator.tf/listings/6051ebf6e204aa851d3a2847 b/o 54

https://backpack.tf/profiles/76561199111073161#!/compare/1615852800/1615939200

https://backpack.tf/profiles/76561198800547001#!/compare/1615939200/1616025600 Puzzle Helmet + Fragmented Photons Yule Hog + stuff, will cap at 54

https://backpack.tf/profiles/76561198021385566#!/compare/1615161600/1615334400

https://backpack.tf/profiles/76561199111073161#!/compare/1615075200/1615161600 quicksold

https://backpack.tf/item/7807948162

https://gladiator.tf/listings/602d9d503acdcfebd66065ec

https://backpack.tf/profiles/76561198841279602#!/compare/1613692800/1613779200

https://backpack.tf/profiles/76561198026639685#!/compare/1613433600/1615420800 unknown amount of keys, had b/o 50

https://backpack.tf/profiles/76561198338567982#!/compare/1610409600/1610582400

https://backpack.tf/profiles/76561198393480198#!/compare/1610841600/1610928000 44 keys

https://backpack.tf/profiles/76561198393480198#!/compare/1610928000/1611014400

https://backpack.tf/profiles/76561198393480198#!/compare/1610928000/1611014400 quicksold

https://backpack.tf/item/6288754728

https://backpack.tf/profiles/76561198286998215#!/compare/1615680000/1616112000

https://backpack.tf/profiles/76561198077490243#!/compare/1616112000/1616284800 55 keys

https://backpack.tf/item/7246781512

https://marketplace.tf/items/tf2/30708;5;u105 51 keys

So sales are 44, 51, 54, 55 and there's a b/o of 50. Buyers were at or above 44 at times in the last few months, but currently down to 33. The lower b/o also indicates 51-55 would probably be high. Will go with the larger range of 44 - 55. 44 was valid when cashew gathered this evidence, blame him for being slow at organizing it into a suggestion