Someone had to do it.

Counter.

Sold for 29 Keys

http://backpack.tf/profiles/76561198062802524#!/compare/1466467200/1466553600

Sold for a Blizzardy Storm Fancy Fedora(28 Keys) and 7 Keys(35 Keys total)

http://backpack.tf/profiles/76561198092471230#!/compare/1464307200/1464393600

Sold for 33 Keys

http://backpack.tf/profiles/76561198077316500#!/compare/1461283200/1461456000

Sold for 28 Keys

http://backpack.tf/profiles/76561198135388328#!/compare/1465516800/1465603200

Sold for 35 Keys

http://backpack.tf/profiles/76561198066950212#!/compare/1459900800/1459987200

Sold for 30 Keys

http://backpack.tf/profiles/76561198135388328#!/compare/1463011200/1463097600

Sold for a Molten Mallard Soviet Gentleman(31 Keys) and ~10 Keys in Sweets(41 Keys total)(B/O was 35)

http://backpack.tf/profiles/76561198186257257#!/compare/1463788800/1463875200

http://www.tf2outpost.com/trade/28157902

Sold for a Max's Severed Head(30 Keys at the time) and 1 Key(31 Keys total)

http://backpack.tf/profiles/76561198081290128#!/compare/1459987200/1460764800

http://backpack.tf/profiles/76561198092128134#!/compare/1460419200/1460505600

Sold for 30 Keys

http://backpack.tf/profiles/76561198135388328#!/compare/1462924800/1463011200

Sales seem to fit, 28-35 Keys should be fine.

Additional Proof/Counter-Proof/Constructive Criticism/Feedback is always appreciated.