https://marketplace.tf/items/tf2/30708;5;u103

$50 / $1.88 = 26.60 keys

$63.33 / $1.89 = 33.51 keys

$79.99 / $1.92 = 41.66 keys https://backpack.tf/item/4689191119

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https://backpack.tf/profiles/76561198084727676#!/compare/1591056000/1592006400

https://backpack.tf/profiles/76561198089478585#!/compare/1591574400/1591660800

added 9 keys & refined for eldritch flame hellmet, better used there

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https://backpack.tf/item/7637645636

https://backpack.tf/item/8064472512

nothing

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https://backpack.tf/profiles/76561198021055079#!/compare/1587686400/1587772800

https://backpack.tf/profiles/76561198024215617#!/compare/1587772800/1587859200

https://bot.tf/stats/listings/MXX06X31

likely 28 keys

//

https://backpack.tf/profiles/76561198024215617#!/compare/1588032000/1588464000

https://backpack.tf/profiles/76561199017581574#!/compare/1586217600/1588377600

mystery hellmet (23 keys) + 11 keys = 34 keys

https://backpack.tf/suggestion/5eb49bea01a0f96c0c666ec9

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https://backpack.tf/profiles/76561199017581574#!/compare/1588464000/1588723200

https://backpack.tf/profiles/76561198372064970#!/compare/1588377600/1588464000

Untraceable

//

https://backpack.tf/profiles/76561198372064970#!/compare/1588464000/1588550400

https://backpack.tf/profiles/76561198210943957#!/compare/1586563200/1588550400

25 keys

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https://backpack.tf/profiles/76561198096856475#!/compare/1592956800/1593043200

https://backpack.tf/profiles/76561198398441774#!/compare/1592784000/1593475200

Untraceable

//

https://backpack.tf/profiles/76561198247802030#!/compare/1591401600/1591833600

https://backpack.tf/profiles/76561198337734785#!/compare/1591401600/1591488000

Untraceable

//

https://backpack.tf/profiles/76561198337734785#!/compare/1591660800/1591747200

https://backpack.tf/profiles/76561198077824457#!/compare/1591574400/1591660800

Untraceable

//

https://backpack.tf/profiles/76561198328984748#!/compare/1589414400/1589500800

https://backpack.tf/profiles/76561198074685139#!/compare/1589241600/1589414400

28 keys

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https://backpack.tf/profiles/76561198074685139#!/compare/1590710400/1590883200

https://backpack.tf/profiles/76561198850266056#!/compare/1590710400/1590796800

Unknown amount of keys, might be 22 keys leaving the 2nd compare?

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https://backpack.tf/profiles/76561198018456402#!/compare/1588291200/1588377600

https://backpack.tf/profiles/76561198204261843#!/compare/1583280000/1589328000

Untraceable

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Sales:

25 27 28 28 34 34 42

https://gyazo.com/90e1ac38fc95d223b4f70d2078b4f585

Buyers 26 keys

This item seems to be on an upward trend, but for the time being, going with 28-34 keys.

Another seller at $79.99 Marketplace, so 28-42 may be possible if that sells.

https://gyazo.com/a879ebd882691a53bf88bcd7d429a70b

Unknown item history because https://gyazo.com/851fdc893d5cbea1e2e8fe7bf5549bf7

super epic