Been waiting to do this one.. (:

Sale 1: Sold for 19 keys + 1.4 key taunt.

http://backpack.tf/profiles/76561198304585778#!/compare/1467417600/1467504000

Using 20 keys

Sale 2: Sold for 19 keys + 1.5 keys in items.

http://backpack.tf/profiles/76561198034183306#!/compare/1467504000/1467590400

19 + 1.5 = 20.5 keys

Sale 3: Sold with Max's Head (23) for Cloudy Moon Outdoorsman (B/O capped at ~50).

http://prnt.sc/bp0v8b & http://prnt.sc/bp0vbr (Credits to |V| Partysalty)

50 - 23 = 27 keys

Sale 4: Sold with Steaming Dapper (25) for C9 Cosa Nostra (45) + 10 keys in items.

http://backpack.tf/profiles/76561198130429617#!/compare/1469750400/1469923200

http://i.imgur.com/2RC6qMG.png

55 - 25 = 30 keys

Sale 5: Sold with TF Logo Muffs for Chiroptera Anger.

http://backpack.tf/profiles/76561198056086416#!/compare/1467590400/1467676800

Invalid due to contributing less than 50% of the sale

Duped Outdoorsman Mini: Sold for Ghosts YWN (54) + 3 keys.

http://backpack.tf/profiles/76561197964171516#!/compare/1466035200/1466121600 (Credits to Foamy)

http://www.tf2outpost.com/trade/28218632 (B/O of ~50)

Using 50 keys

Dapper Mini: http://backpack.tf/suggestion/57a03c53c440456bdb1ed839

Using 25 keys

20-30 seems fine as a result.

Any help/criticism is appreciated.