Sale 1:

Sold for Neutron Star Wing Mann (Mini at 10 below)

No outpost

Seller: https://backpack.tf/profiles/76561198271428863#!/compare/1494460800/1494547200

Buyer: https://backpack.tf/profiles/76561198240353648#!/compare/1494460800/1494547200

X = 10

Sale 2:

Sold for 9 keys

No outpost

Seller: https://backpack.tf/profiles/76561197963500354#!/compare/1494028800/1494115200

Buyer: https://backpack.tf/profiles/76561198212868655#!/compare/1493856000/1494115200

X = 9

Sale 3:

Sold with cheap cosmetic for Stormy Magnificent Mongolian (9) + 1 rec

http://www.tf2outpost.com/trade/28989468 - B/O of 10

Seller: https://backpack.tf/profiles/76561198212868655#!/compare/1494201600/1494288000

Buyer: https://backpack.tf/profiles/76561198271428863#!/compare/1494201600/1494288000

X = 9

Neutron Star Wing Mann Mini:

Sold for 10 keys

No outpost (B/O was 10 though)

Seller: https://backpack.tf/profiles/76561198021055079#!/compare/1501718400/1501804800

Buyer: https://backpack.tf/profiles/76561198110017602#!/compare/1501718400/1501804800

http://imgur.com/a/DpiJr

X = 10

Sellers:

~9.23 keys:

http://i.imgur.com/keYA0TI.png - 9 days

~9.33 keys:

http://i.imgur.com/vyFUXor.png - 19 days

10 keys:

http://i.imgur.com/IDz3wtH.png - 1 month

Sales at:

9 (2x)

10

Given the current sellers for less than 10, and the month-old seller at 10, this item doesn’t appear to sell for 10 keys well. Alternatively, this can be used to update the Wing Mann. Excluding 10.

Going with 9 flat.