Four month old price.

Resuggestion of https://backpack.tf/suggestion/60016f524fbb7a00a41c7521 - see there for untraceables.

Sale 1:

https://marketplace.tf/items/tf2/30120;5;u61 - new sale at $34.99 (17 keys)

Credit to Blaze.

Sale 2:

https://backpack.tf/item/2208514531

https://backpack.tf/profiles/76561198148712143#!/compare/1606003200/1606089600

https://backpack.tf/profiles/76561198376879464#!/compare/1606003200/1606089600

14 keys + Strange Beggar's Bazooka.

Valuing Beggar's at 12 ref: https://gyazo.com/0ebacaced322c769801c3b84ee661459

14.2 keys, rounded to 14.

Sale 3:

https://marketplace.tf/items/tf2/30120;5;u61

January 5, 2021: $29.99 - $29.99 / $2.12 = 14.15 keys

Sale 4:

https://marketplace.tf/items/tf2/30120;5;u61

October 23, 2020: $29.99 - $29.99 / $1.86 = 16.12 keys

Sale 5:

https://backpack.tf/item/2208514531

https://backpack.tf/profiles/76561199037910054#!/compare/1606780800/1606867200

https://backpack.tf/profiles/76561198349986297#!/compare/1606780800/1606867200

1:1 for Circling TF Logo Antarctic Eyewear.

Mini for Circling TF Logo Antarctic Eyewear:

https://marketplace.tf/items/tf2/30977;5;u11

Nov 9, 2020: $34 - $34 / $1.80 = 18.89 keys

Dec 12, 2020: $39.99 - $39.99 / $1.89 = 21.16 keys

19-21 keys, 20 keys median.

Sale 6:

https://backpack.tf/item/2208514531

https://backpack.tf/profiles/76561198851597200#!/compare/1608854400/1608940800

https://backpack.tf/profiles/76561198286956154#!/compare/1608508800/1608940800

16 keys.