Only one recent sale valued @ 21 keys

Sold with 2 keys for Stormy Gaze (25k, outdated)

https://backpack.tf/profiles/76561198388060316#!/compare/1525564800/1525651200

Gaze Mini - Sold with 4 keys for a Pro KS Aussie Knife

https://backpack.tf/profiles/76561198093438754#!/compare/1522368000/1522454400

Knife Micro - Sold consistently for ~$54 these past two months in mp.tf

https://marketplace.tf/items/194;11;australium;kt-3

Keys are $1.97

54/1.97 = ~27 keys (semi-consistent with classified prices: https://backpack.tf/stats/Strange/Australium%20Professional%20Killstreak%20Knife/Tradable/Craftable )

CALCULATIONS:

Gaze = 27 - 4

= 23 keys

Shellmet = 23 - 2

= 21 keys

Therefore suggested value of 21 keys