https://bot.tf/stats/item?def=44&q=14&craft=1

Bot.tf buys past 30 days:

1 @ 6 keys, 16.88 ref

Marketplace.tf sales past 91 days:

14.99 / 1.85 = 8.10

14.84 / 1.79 = 8.29

The average is 8.20 keys.

The range is 8.10 - 8.30 keys.

SCM sales past 91 days:

29.02 / 2.33 = 12.44

Not counting SCM sale since current seller at 8.99 keys. (and unsold for 1 month I guess, can't tell since the bot relists every 30 mins https://backpack.tf/item/7178076746)

Not counting bot.tf sale since current buyers above it.

Final range 8.1 - 8.3 keys.