Sale 1:

Sold for Kill-a-Watt Brown Bomber (22.5)

Seller: https://backpack.tf/profiles/76561198064093548#!/compare/1579305600/1579392000

Buyer: https://backpack.tf/profiles/76561198311498888#!/compare/1579219200/1579305600

https://backpack.tf/item/7956484550

23 keys

Sale 2:

Sold for 20 keys

Seller: https://backpack.tf/profiles/76561198305494036#!/compare/1584230400/1584316800

Buyer: https://backpack.tf/profiles/76561198983435133#!/compare/1584230400/1584316800

https://backpack.tf/item/7956484550 (gambled afterwards)

20 keys

Sale 3:

Sold for 18 keys + some ref

Seller: https://backpack.tf/profiles/76561198311498888#!/compare/1580688000/1580774400

Buyer: https://backpack.tf/profiles/76561198207603105#!/compare/1580515200/1580774400

https://backpack.tf/item/7956484550

18 keys

Sale 4:

Sold for 17 keys + ~1 key in ref

Seller: https://backpack.tf/profiles/76561198311498888#!/compare/1582675200/1582761600

Buyer: https://backpack.tf/profiles/76561198024766381#!/compare/1582588800/1582761600

https://backpack.tf/item/7955959290

18 keys

Sale 5:

Sold to a bot for 15 keys + 23 ref

Seller: https://backpack.tf/profiles/76561198192602363#!/compare/1584230400/1584316800

Buyer: https://backpack.tf/profiles/76561198305494036#!/compare/1584230400/1584316800

https://backpack.tf/item/7956484550

https://i.imgur.com/1F9HmmM.png - bot.tf confirms

15 keys

Marketplace Sales:

https://marketplace.tf/items/tf2/30355;5;u62

$52, Jan 22nd

$49.70, Feb 17th (2x)

$35, March 7th

$50, March 21st

$50, March 23rd

https://backpack.tf/item/7955959290 - 22nd Jan

https://bot.tf/stats/listings/Y7DVJ9ZK - No B/O

https://manic.tf/keyprice/?at=2020-01-22&price=52 - $52 / $1.78 = 29.21 keys

https://backpack.tf/item/7956484550 - 17th Feb

https://backpack.tf/item/7956466932 - 17th Feb again (gambled afterwards)

https://bot.tf/stats/listings/4OVP8VZP - B/O of 35 for one of them, no B/O for the other

http://manic.tf/keyprice?at=2020-02-17&price=49.7 - $49.7 / $1.77 = 28.08 keys (2x)

https://backpack.tf/item/7956811498 - March 7th

https://bot.tf/stats/listings/MQ9OKNLP - No B/O

http://manic.tf/keyprice?at=2020-03-07&price=35 - $35 / $1.70 = 20.59 keys

https://backpack.tf/item/7957494649 - March 21st, or 23rd

https://bot.tf/stats/listings/4J9G5Z6P - No B/O

Can’t find the history for the other sale around this time.

http://manic.tf/keyprice?at=2020-03-21&price=50 - $50 / $1.68 = 29.76 keys

https://manic.tf/keyprice/?at=2020-03-23&price=50 - $50 / $1.68 = 29.76 keys

After rounding, we have:

28 (2x)

30 (2x)

Other Sales:

https://backpack.tf/item/7956750481 (#1-3)

https://backpack.tf/item/7955959290 (#4)

https://backpack.tf/item/2666864277 - gambled

https://backpack.tf/item/7956327481 - mannco/scrap

https://backpack.tf/item/7956811498 - marketplace/gambling/mannco/scrap etc.

#1

Untraceable

https://backpack.tf/profiles/76561198355089825#!/compare/1582329600/1582416000

https://backpack.tf/profiles/76561198305494036#!/compare/1582329600/1582416000

https://i.imgur.com/1F9HmmM.png - labelled as ~15 keys

#2

Untraceable

https://backpack.tf/profiles/76561198305494036#!/compare/1582329600/1582416000

https://backpack.tf/profiles/76561198160856661#!/compare/1582416000/1582502400

https://i.imgur.com/1F9HmmM.png - labelled as 18 keys

#3

Untraceable

https://backpack.tf/profiles/76561198160856661#!/compare/1582416000/1582502400

https://backpack.tf/profiles/76561198886850124#!/compare/1582416000/1582502400

Gambled afterwards.

#4

Bulk for pure?

https://backpack.tf/profiles/76561198861666666#!/compare/1582675200/1582761600

https://backpack.tf/profiles/76561198311498888#!/compare/1582675200/1582761600

Sellers/Buyers:

https://i.imgur.com/gij4DWR.png

https://backpack.tf/item/7956811498 - 30 keys

https://backpack.tf/item/7957524710 - 34 keys

https://backpack.tf/item/7093192426 - 34 keys

Buyers at ~17 keys

Sales at:

15

18 (2x)

20

21

23

28 (2x)

29

30 (2x)

15 is an outlier given the buyers for higher. Excluding 15.

Taking 18-30.