Lets see.

Sale 1: Sold with multiple unusuals and other items for Scorching Flames Ground Control

http://backpack.tf/profiles/76561198011321852/#!/compare/1455350400/1455436800

Should be used to price the Ground Control.

Sale 2: Sold for 21 keys+Strange Villian's Veil[4 keys]

http://backpack.tf/profiles/76561198047855072/#!/compare/1457251200/1457769600

21+4=25 keys

Sale 3: Sold with a key for Disco Beat Down Samur-Eye[36 keys]

http://www.tf2outpost.com/trade/27948484 b/o was 30 keys

http://backpack.tf/profiles/76561198183849619/#!/compare/1457683200/1457769600

36-1=35 keys

b/o was 30, so capping it there.

So, I have sales at 25 and 30. Making this a range of 25-30 keys.