Sale 1:

https://mannco.store/item/14995 - Jun 19

$38.25 / $1.84 = 20.78 keys, No B/O - https://backpack.tf/item/8082780374

= 21 Keys.

Sale 2:

https://backpack.tf/profiles/76561198144089680#!/compare/1592438400/1592697600

https://backpack.tf/profiles/76561199005154104#!/compare/1592524800/1592697600

Untrace.

Sale 3:

https://backpack.tf/profiles/76561199005154104#!/compare/1592524800/1592697600

https://backpack.tf/profiles/76561198342161127#!/compare/1592611200/1592697600

Bulk

Sale 4:

https://backpack.tf/profiles/76561198342161127#!/compare/1592784000/1592870400

https://backpack.tf/profiles/76561198057460348#!/compare/1592870400/1593561600

Sold for Disco Beat Down Lucky Shot (28.5) + 5 Keys = 33.5 keys, https://bot.tf/stats/listings/4ZPDD8R1 - B/O 30 Keys.

= 30 Keys.

Sale 5:

https://marketplace.tf/items/tf2/31045;5;u19 - May 8

$60 / $1.89 = 31.75 keys = 32 Keys, No B/O

= 32 Keys.

https://backpack.tf/suggestion/5f191ff1f45a4d6a515e63c9#comment-5f501830938ea06fa6015741

Scourge:

https://marketplace.tf/items/tf2/31045;5;u19

https://backpack.tf/item/8709141333

$69 / $1.81 = 38.12 keys

new sale here points to 21 being an outlier,

https://bot.tf/stats/listings/4P0Z2PK3 ----- listing at 33 from not long ago (thanks K1ng)

though 38 should also not be included.

This should be resuggested at 30 - 32 keys.