Updating 3-year old price.

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

Buy orders start at 7.45 keys.

Sell orders start at 9.7 keys.

No bot.tf sales in 30 days.

No viable Marketplace.tf sales in 30 days.

SCM Sales:

https://steamcommunity.com/market/listings/440/Strange%20Grim%20Tweeter

1 Sold for $21.81/ 2.33 = 9.36, ~9.35 keys.

2 Sold for $21.00/ 2.28 = 9.21, ~9.2 keys.

1 Sold for $21.85/ 2.31 = 9.45 keys.

1 Sold for $23.00/ 2.36 = 9.74, ~9.75 keys.

1 Sold for $14.84/ 2.30 = 6.45 keys.

Excluding all other sales due to them being either too low for current buy orders or too high for current sell orders. Going with 9.2 - 9.45 keys.