Suggestion version 2.0 w/ fixed price ranges + updated buy and sell orders.

https://backpack.tf/classifieds?item=Antarctic%20Parka&quality=11&tradable=1&craftable=1&australium=-1&killstreak_tier=0

Buy Orders start at 7.46, ~7.45 keys.

Sell Orders start at 7.78, ~7.8 keys.

Bot.tf Sales:

https://ibb.co/CWwKD56

https://ibb.co/jRJ1Fhr

1 Sold for 7.79, ~7.8 keys.

1 Sold for 8.74, ~8.75 keys.

Marketplace.tf Sales:

https://ibb.co/Jcfd26P

1 Sold for $14.00/ 1.87 = 7.48, ~7.5 keys.

1 Sold for $15.30/ 1.83 = 8.36, ~8.35 keys.

1 Sold for $15.00/ 1.85 = 8.1 keys.

1 Sold for $15.49/ 1.88 = 8.23, ~8.25 keys.

SCM Sales:

https://ibb.co/x1TGMJ3

1 Sold for $16.59/ 2.32 = 7.15 keys.

1 Sold for $20.77/ 2.32 = 8.95 keys.

2 Sold for $16.70/ 2.34 = 7.13, ~7.15 keys.

1 Sold for $16.85/ 2.33 = 7.23, ~7.25 keys.

Excluding all other sales due to being either too low for current buy orders, or too high for current sell orders. Going with 7.5 - 7.8 keys.