Using last month.

Sales 1-5:

Sold for $15, $14.99, $14, and $13.80 (2x) on marketplace.tf

https://marketplace.tf/items/30673;5;u3005

https://backpack.tf/item/6297626375 - Can’t pinpoint which sale this was, no visible B/O anyways

https://backpack.tf/item/6259729374 - Same here

https://backpack.tf/item/4309091219 - Same here

https://backpack.tf/item/5400649489 - May have been another, as the seller receives nothing, but same situation as the ones above.

http://manicbot.me/keyprice/?at=2018-07-25 - 13.80/1.94 = ~7.11, rounds to 7

http://manicbot.me/keyprice/?at=2018-07-28 - 13.80/1.99 = ~6.93, rounds to 7

http://manicbot.me/keyprice/?at=2018-07-30 - 14/1.96 = ~7.14, rounds to 7

http://manicbot.me/keyprice/?at=2018-08-01 - 14.99/1.94 = ~7.73, rounds to 7.5

http://manicbot.me/keyprice/?at=2018-08-02 - 15/1.93 = ~7.77, rounds to 8

X = 8

X = 7.5

X = 7 (3x)

Sale 6:

Sold for a bunch of junk

Seller: https://backpack.tf/profiles/76561197981387701#!/compare/1532217600/1532304000

Buyer: https://backpack.tf/profiles/76561198094083224#!/compare/1532217600/1532304000

https://backpack.tf/item/4408803788

Better off not using a sale like this.

Sale 7:

Sold for Mega Strike Oblooterated

Seller: https://backpack.tf/profiles/76561198204042832#!/compare/1517011200/1532390400

Buyer: https://backpack.tf/profiles/76561198353195301#!/compare/1532304000/1532390400

https://backpack.tf/item/4408803788

Can be used on the Oblooterated.

Untraceable bot.tf trades:

https://backpack.tf/profiles/76561198382589541#!/compare/1532131200/1532217600

https://backpack.tf/profiles/76561198394457682#!/compare/1531353600/1532304000

https://backpack.tf/item/4400332101

https://i.imgur.com/raoyObq.png - 6 keys + 5 ref, according to bot.tf. Only 5 ref matches here.

https://backpack.tf/profiles/76561198288608358#!/compare/1532649600/1533081600

https://backpack.tf/profiles/76561198382589541#!/compare/1532995200/1533081600

https://backpack.tf/item/4255274099

https://i.imgur.com/raoyObq.png - 4 keys + 1 ref here, according to bot.tf. Nothing matches.

https://backpack.tf/profiles/76561198382589541#!/compare/1533254400/1533340800

https://backpack.tf/profiles/76561198192323878#!/compare/1533168000/1533340800

https://backpack.tf/item/4255274099

https://i.imgur.com/raoyObq.png - 7 keys + 1 ref here, according to bot.tf. Nothing matches.

https://backpack.tf/profiles/76561198305676157#!/compare/1534370400/1534456800

https://backpack.tf/item/4443460821

https://i.imgur.com/raoyObq.png - 6 keys and 28 ref here, according to bot.tf. Buyer’s compare is unavailable, though the seller’s compare link does show 6 keys and 28 ref obtained in one go. Couldn’t trace the buyer as the items all come from bots. Even if the buyer’s backpack does get scanned, and this sale does end up being correct, it would still support the low-end, and will leave the range unaffected.

These are all the bot.tf trades in the last month.

Sellers:

https://i.imgur.com/AJKQ7Ml.png

~6.8 keys:

https://backpack.tf/item/4400332101

8 keys:

https://backpack.tf/item/4709751924

9 keys:

https://backpack.tf/item/5370865527

12 keys:

https://backpack.tf/item/4258933910

24 keys:

https://backpack.tf/item/5451550670

Sales at:

7 (3x)

7.5

8

Going with 7-8.