Thanks Xergoyf, for the help :)

Eerie Lightning Taunt: The Bunnyhopper

Sale 1

https://backpack.tf/profiles/76561198116084478#!/compare/1587340800/1592352000

https://backpack.tf/profiles/76561197962704807#!/compare/1588377600/1592352000

Bulk

Sale 2

https://backpack.tf/profiles/76561197962704807#!/compare/1588377600/1592352000

https://backpack.tf/profiles/76561198160856661#!/compare/1592352000/1592438400

Untrace

Sale 3

https://backpack.tf/profiles/76561198160856661#!/compare/1592352000/1592438400

https://backpack.tf/profiles/76561198288608358#!/compare/1592697600/1593907200

Untrace

Sale 4

https://backpack.tf/profiles/76561198288608358#!/compare/1592697600/1593907200

https://backpack.tf/profiles/76561198453530349#!/compare/1593820800/1593907200

Untrace

Sale 5

https://backpack.tf/profiles/76561198453530349#!/compare/1594252800/1594339200

https://backpack.tf/profiles/76561198362096103#!/compare/1594080000/1594339200

Near ID match 4 keys.

https://bot.tf/stats/listings/4KV9D8L0 <- Bot listed for ~ 4 keys too. Taking 4 keys.

Sale 6

https://backpack.tf/profiles/76561198015950668#!/compare/1592265600/1592352000

https://backpack.tf/profiles/76561198858685510#!/compare/1592265600/1592352000

Untrace

Sale 7

https://backpack.tf/profiles/76561198858685510#!/compare/1592352000/1592524800

https://backpack.tf/profiles/76561197992295262#!/compare/1592265600/1592524800

Nearest ID match the 5 keys. Since some of them came from the buyer and the keys were received together, most likely to be it.

Sale 8

https://backpack.tf/profiles/76561198119198857#!/compare/1592784000/1592870400

https://backpack.tf/profiles/76561198302115343#!/compare/1592697600/1592870400

Sold for a Dead Presidents Katyusha + 10 ref.

Sellers at ~ 6.5 and buyers at ~6. Safe to price it at 6 - 6.5. Taking 6.5

Sale 9

https://backpack.tf/profiles/76561198302115343#!/compare/1592697600/1592870400

https://backpack.tf/profiles/76561198406114836#!/compare/1592870400/1593043200

Could only trace a strange part and a strange skin being traded worth less than a key, definitely too low.

Sale 10

https://backpack.tf/profiles/76561198406114836#!/compare/1593561600/1593648000

https://backpack.tf/profiles/76561198018598822#!/compare/1593475200/1593648000

Untrace

Sale 11

https://backpack.tf/profiles/76561198018598822#!/compare/1593648000/1593993600

https://backpack.tf/profiles/76561198202186637#!/compare/1593907200/1593993600

Bulk

Marketplace sale: https://marketplace.tf/items/tf2/30920;5;u3027

1. Sold on 6/13/2020 for $15.99 / $2.00 = 8.00 keys

2. Sold on 6/22/2020 for $20 / $1.98 = 10.10 keys ~ 10

Sales at 4, 5, 6.5, 8, and 10.

Dropping the 4 and 10 keys sale to keep a more narrow range.

Pricing this at 5 - 8 keys.