Sale #1:

Sold for Steaming Slouch + Logo Prussian Pickelhaube + 10 keys + ~2 keys in items/metal

http://backpack.tf/profiles/76561198110622804?time=1432710000 (May 27th)

http://backpack.tf/profiles/76561198110622804?time=1432796400 (May 28th)

Lots of outdated stuff, but it's probably around 40 keys.

Sale #2:

http://www.tf2outpost.com/trade/26022720

Sold for an Electrostatic Tyrant's Helm (outdated)

http://backpack.tf/profiles/76561198046398252?time=1432450800 (May 24th)

http://backpack.tf/profiles/76561198046398252?time=1432537200 (May 25th)

Sale #3:

http://www.tf2outpost.com/trade/25786659

Sold for Blizz Ze Goggles (15) + Gfetti Kabuto (25)

http://backpack.tf/profiles/76561198068143570?time=1432191600 (May 21st)

http://backpack.tf/profiles/76561198068143570?time=1432278000 (May 22nd)

(15 + 25) * 0.9 = 36 keys

Sale #4:

http://www.tf2outpost.com/trade/26046819

Quick-sold for Steaming Festivizer (13) + 16 keys

http://backpack.tf/profiles/76561198043536092?time=1432623600 (May 26th)

http://backpack.tf/profiles/76561198043536092?time=1432710000 (May 27th)

(13 * 0.9) + 16 = 27.7; rounded to 28 keys

Was sold in less than a day for mostly pure.

Sale #5:

http://www.tf2outpost.com/trade/26029206

Sold for GE Jumper's Jeepcap (39)

http://backpack.tf/profiles/76561198041582015?time=1432191600 (May 21st)

http://backpack.tf/profiles/76561198041582015?time=1432537200 (May 25th)

Should be taken without overpay since the seller was looking for an Energy Soldier hat.

39 keys

Sale #6:

http://www.tf2outpost.com/trade/25302956

Sold for an Australium Scattergun (35) + 2 keys

http://backpack.tf/profiles/76561198073376363?time=1425801600 (March 8th)

http://backpack.tf/profiles/76561198073376363?time=1425884400 (March 9th)

(35 * 0.9) + 2 = 33.5; rounded to 34 keys