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

Buy Orders start at 42.1, ~42 keys.

Sell Orders primarily start at 52 keys. I'm not including the 48 keys sell order because I believe that's either an outdated sell order, or a quicksell order. Also, it's the only sell order that's not in the low 50s compared to all the other sell orders available, so that's my judgment.

No Bot.tf Sales in the last 30 days.

Marketplace.tf Sales:

https://ibb.co/k9xcyk7

1 Sold for $84/ 1.87 = 44.9, ~45 keys.

1 Sold for $94.99/ 1.85 = 51.34, ~51 keys.

1 Sold for $94.99/ 1.89 = 50.25, ~50 keys.

1 Sold for $99.40/ 1.85 = 53.72, ~54 keys.

SCM Sales:

https://ibb.co/TbRsgKr

1 Sold for $86.25/ 2.23 = 38.6, ~39 keys.

1 Sold for $86.24/ 2.24 = 38.5, ~39 keys.

1 Sold for $88.20/ 2.34 = 37.69, ~38 keys.

Excluding all sales aside from those within the 42-52 key range, due to them either being too low for the average buy orders, or too high for the average sell order range. Going with 45 - 51 keys.