Sold for 13.75 keys mixed.

https://backpack.tf/profiles/76561198139220324#!/compare/1557273600/1557360000

Neutron Star Wide-Brimmed Bandito - 16 keys

Pink as Hell Killer Exclusive - 23 ref

Bot buying pink as hell killer exclusive for 23 ref.

Strange Warrior Spirit - 2.55 ref

Strange Turbine Torcher Flame Thrower (Field-Tested) - $0.38 on SCM, 9.5 ref

Seller added 3 keys.

Items worth 35.05 ref, ~0.75 keys.

16.75 mixed for Circling Heart Field Cap + 3 keys. 16.5-3=13.5

May be subject to change, but for now 13.5 keys is the most recent sale. The sale before this one was for another unpriced unusual.