Resuggestion: https://backpack.tf/suggestion/5e9386292a01d6778c6be555

Sale 1-3:

https://marketplace.tf/items/tf2/31000;5;u113

$29.99 / $1.78 = 16.85 keys // https://backpack.tf/item/7256020851

$10.01 / $1.77 = 5.66 keys - under buyers

$29.99 / $1.69 = 17.75 keys // https://backpack.tf/item/8247959541

Sale 4:

using on Requiem

https://backpack.tf/profiles/76561198402240423#!/compare/1582502400/1582675200

https://backpack.tf/profiles/76561198195734346#!/compare/1582588800/1582675200

Sale 5:

9 keys - under buyers

https://backpack.tf/profiles/76561198146569609#!/compare/1579564800/1585180800

https://backpack.tf/profiles/76561198841279602#!/compare/1579564800/1579651200

Sale 6:

12 keys

https://backpack.tf/profiles/76561198841279602#!/compare/1586217600/1586304000

https://backpack.tf/profiles/76561198262869483#!/compare/1585958400/1586304000

Sale 7:

bp sell

https://backpack.tf/profiles/76561198262869483#!/compare/1586304000/1586390400

https://backpack.tf/profiles/76561199019167200#!/compare/1585958400/1586390400

Sale 8:

untrace

https://backpack.tf/profiles/76561199019167200#!/compare/1585958400/1586390400

https://backpack.tf/profiles/76561198363395191#!/compare/1586304000/1586390400

========================================================================

Credit to Scourge:

#1 bulk

https://backpack.tf/profiles/76561198211161901#!/compare/1574294400/1585958400

https://backpack.tf/profiles/76561198040186479#!/compare/1585267200/1585440000

https://gyazo.com/cdb3f7e0cc11bae5ffee947c7c449a4a

#2 - 16 keys

https://backpack.tf/profiles/76561198040186479#!/compare/1586044800/1586131200

https://backpack.tf/profiles/76561198176503971#!/compare/1584057600/1586649600

https://gyazo.com/7b108788d73576e096c1772dbd27c59a

========================================================================

new sales:

6 keys? probs something missing

https://backpack.tf/profiles/76561198163827950#!/compare/1587945600/1588032000

https://backpack.tf/profiles/76561198436575899#!/compare/1587859200/1587945600

10 keys

https://backpack.tf/profiles/76561198436575899#!/compare/1588204800/1588291200

https://backpack.tf/profiles/76561198302826667#!/compare/1588291200/1588377600

15 keys

Winter Spirit Bad Pipes(8) + 7 keys

https://backpack.tf/profiles/76561198302826667#!/compare/1588377600/1588464000

https://backpack.tf/profiles/76561198877320307#!/compare/1588377600/1588464000

pipes: https://backpack.tf/suggestion/5eb02ca91a8c5b394c537c92

scrap bot then scrap auction: https://backpack.tf/item/7262821920

those MP sellers sold: https://marketplace.tf/items/tf2/31000;5;u113

$19.95 / $1.85 = 10.78 keys

$22.99 / $1.88 = 12.23 keys

================================================================================

All sales:

6,9,10,11,11,12,12,15,16,17,18

buyers at 9.34 keys: https://imgur.com/a/7ZP7qyJ

Blaze:

"given there are still a bunch of lower sellers and all these new recent sales are lower compared to the original suggestion, maybe something like 11-15 would work here taking 3 low and 3 high outliers"