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

Buy Orders start at 9.47, ~9.45 keys.

Sell Orders start at 10.5 keys.

Bot.tf Sales:

https://ibb.co/m9YRC9V

1 Sold for 9.07, ~9.05 keys.

1 Sold for 8.82, ~8.8 keys.

Marketplace.tf Sale:

https://ibb.co/BG6rJ6L

1 Sold for $20.00/ 1.84 = 10.86, ~10.85 keys.

SCM Sales:

https://ibb.co/gtXgC6p

1 Sold for $21.05/ 2.24 = 9.39, ~9.4 keys.

1 Sold for $25.80/ 2.32 = 11.12, ~11.1 keys.

1 Sold for $23.24/ 2.25 = 10.32, ~10.3 keys.

Excluding any other sales, due to them being either too low for buy orders, or too high for sell orders. I also had to resort to using a sale that's 5 days late, but due to the lack of actual in-range sales, and the fact that it's barely late, it's a call of judgment to use it anyways. Going with 10.3 keys solid.