Listed gladiator sales from previous month and month before that (may overlap with sales below):

https://gladiator.tf/sales?item=Pyroland%20Nightmare%20Glow%20from%20Below&at=2021-11-21T20:49:08.204Z

https://gladiator.tf/sales?item=Pyroland%20Nightmare%20Glow%20from%20Below&at=2021-10-21T20:49:08.204Z

1 @ 8 keys 20.22 ref

1 @ 8 keys 20.77 ref

1 @ 8 keys 21.22 ref

1 @ 8 keys 20.11 ref

1 @ 8 keys 21.22 ref

1 @ 8 keys 22.22 ref

1 @ 9 keys

https://marketplace.tf/items/tf2/31149;5;u159

$21.99/1.83=~12k

https://mannco.store/item/440-pyroland-nightmare-unusual-glow-from-below

$16.95/1.73=~9.8k

$13.72/1.72=~8k

$13.7/1.64=~8.4k

https://backpack.tf/item/9363711666

https://backpack.tf/item/10688978349

https://backpack.tf/profiles/76561199166760030#!/compare/1636243200/1636329600

https://backpack.tf/profiles/76561199132665029#!/compare/1636243200/1636329600

8k 3ref

move to MP

https://backpack.tf/item/9870679067

https://backpack.tf/profiles/76561198181015431#!/compare/1637107200/1637452800

https://backpack.tf/profiles/76561199107865875#!/compare/1637107200/1637452800

untrace buy order

https://backpack.tf/item/9736125246

https://backpack.tf/profiles/76561198453530349#!/compare/1639008000/1639094400

https://gladiator.tf/listings/61b29eac9d2ff47d376845ea

untrace, snapshot suggests ~8.5k

https://backpack.tf/item/9390813938

https://backpack.tf/profiles/76561198233493508#!/compare/1635724800/1635811200

https://backpack.tf/profiles/76561198212072039#!/compare/1634515200/1635811200

untrace

https://backpack.tf/profiles/76561198212072039#!/compare/1635811200/1637107200

https://backpack.tf/profiles/76561198252696376#!/compare/1635811200/1635897600

untrace

https://backpack.tf/profiles/76561198252696376#!/compare/1635811200/1635897600

https://backpack.tf/profiles/76561198055093291#!/compare/1635811200/1635897600

untrace

https://backpack.tf/profiles/76561198055093291#!/compare/1635724800/1635811200

https://backpack.tf/profiles/76561198000694458#!/compare/1635724800/1635811200

untrace buy order

https://backpack.tf/item/9363711666

Mannco.store sale

https://backpack.tf/profiles/76561199171997673#!/compare/1635379200/1635465600

https://backpack.tf/profiles/76561198850274253#!/compare/1635379200/1635465600

some ref matches, otherwise untrace

https://backpack.tf/profiles/76561198850274253#!/compare/1635811200/1635897600

https://backpack.tf/profiles/76561198050518375#!/compare/1635811200/1635897600

https://gladiator.tf/listings/6179de77f109b5d38ec9bf4e

not sure if traceable, no listing snapshot, most likely between 8.5-9.5k

https://backpack.tf/profiles/76561198050518375#!/compare/1637107200/1637193600

only a strangifier matches

https://backpack.tf/item/9337082352 - dunno

https://backpack.tf/item/9312585105

https://backpack.tf/profiles/76561198207541888#!/compare/1634515200/1636329600

https://backpack.tf/profiles/76561199125443371#!/compare/1634515200/1636329600

untrace buy order

https://backpack.tf/profiles/76561199125443371#!/compare/1634688000/1634774400

https://backpack.tf/profiles/76561199203995551#!/compare/1634688000/1634774400

untrace

https://backpack.tf/profiles/76561199203995551#!/compare/1634688000/1634774400

https://backpack.tf/profiles/76561198964146509#!/compare/1634688000/1634774400

untrace

https://backpack.tf/profiles/76561198964146509#!/compare/1634688000/1634774400

https://backpack.tf/profiles/76561199111658162#!/compare/1634688000/1634774400

https://gladiator.tf/listings/6170b2f098d47ef00809b0dc

potentially 8k 21ref buy order

https://backpack.tf/profiles/76561199111658162#!/compare/1634860800/1634947200

https://backpack.tf/profiles/76561198841279602#!/compare/1634860800/1634947200

untrace

https://backpack.tf/item/9308851956

https://backpack.tf/profiles/76561198177146103#!/compare/1636416000/1636502400

https://backpack.tf/profiles/76561199110809353#!/compare/1636416000/1636502400

untrace

https://backpack.tf/profiles/76561199110809353#!/compare/1638748800/1638835200

https://backpack.tf/profiles/76561198371959919#!/compare/1638403200/1638835200

untrace

https://backpack.tf/profiles/76561198371959919#!/compare/1638835200/1639008000

https://backpack.tf/profiles/76561198048139829#!/compare/1638403200/1639267200

untrace

Classies: https://backpack.tf/stats/Unusual/Glow%20from%20Below/Tradable/Craftable/159

Two sellers at ~8.6k, one seller above 9k. Buyers at ~8.3k.

Since the 9k sale from gladiator doesn't seem verifiable (and excluding sales above that), taking 8-8.5k as range.