Sale 1:

Sold for 8 keys + 15 ref

Seller: https://backpack.tf/profiles/76561198344933095#!/compare/1524355200/1524441600

Buyer: https://backpack.tf/profiles/76561198080895481#!/compare/1524355200/1524441600

Bot.tf confirms: https://i.imgur.com/ETJCNDp.png

X = 8.5

Sale 2:

Sold for 8 keys + 16 ref

Seller: https://backpack.tf/profiles/76561198344933095#!/compare/1522627200/1522713600

Buyer: https://backpack.tf/profiles/76561198100128947#!/compare/1522627200/1522713600

Bot.tf confirms: https://i.imgur.com/ETJCNDp.png

X = 8.5

Sale 3:

Sold for 7 keys

Seller: https://backpack.tf/profiles/76561198413660453#!/compare/1522195200/1522368000

Buyer: https://backpack.tf/profiles/76561198089253101#!/compare/1522195200/1522281600

X = 7

Sale 4:

Sold for Planets Otolaryngologist’s Mirror + Cat’s Pajamas (~1.5)

No outpost

Seller: https://backpack.tf/profiles/76561198100128947#!/compare/1523059200/1523232000

Buyer: https://backpack.tf/profiles/76561198375681800#!/compare/1523145600/1523491200

Will be pretty high without a B/O to cap at, excluding.

Sale 5:

Sold for Aces High Gauzed Gaze + 1 key and minor items

No outpost

Seller: https://backpack.tf/profiles/76561198322876605#!/compare/1522972800/1523059200

Buyer: https://backpack.tf/profiles/76561198290852109#!/compare/1522454400/1523059200

Same situation as Sale 4, excluding.

Sale 6:

Bulk for Strange Green Confetti Patriot Peak

Seller: https://backpack.tf/profiles/76561198109281673#!/compare/1522713600/1522886400

Buyer: https://backpack.tf/profiles/76561198118141692#!/compare/1522800000/1522886400

Sale 7:

Bulk for Mystery Pullover

Seller: https://backpack.tf/profiles/76561198118141692#!/compare/1523059200/1523145600

Buyer: https://backpack.tf/profiles/76561198232041512#!/compare/1523059200/1523145600

Sale 8:

Bulk for Showstopper Soldier’s Requiem

Seller: https://backpack.tf/profiles/76561198135674042#!/compare/1523836800/1523923200

Buyer: https://backpack.tf/profiles/76561198063640894#!/compare/1523750400/1523836800

Sale 9:

Bulk for Peace Sign Brass Bucket

Seller: https://backpack.tf/profiles/76561198089253101#!/compare/1522195200/1522281600

Buyer: https://backpack.tf/profiles/76561198208266432#!/compare/1522108800/1522281600

Sellers:

8 keys:

https://i.imgur.com/XA7ECYK.png

https://backpack.tf/item/4256867616

9 keys:

https://i.imgur.com/N9HqsUJ.png

https://backpack.tf/item/5426247250

31 keys:

https://i.imgur.com/9Qj9rAp.png

https://backpack.tf/item/4194891784

http://www.tf2outpost.com/trade/29477347

SCM: (Taking keys as $2.47)

https://i.imgur.com/875KGSc.png (Only the first 3 are worth looking at)

$21.78 (~8.82 keys)

$28.99 (~11.64 keys)

$29.99 (~12.14 keys)

Sales at:

7

8.5 (2x)

https://i.imgur.com/Wkx1PDW.png - Buyers at 7+ keys, excluding 7.

Aged seller at 8 keys, using that as the low-end.

Going with 8-8.5 keys.