Sale 1:

Sold for 25 keys

No outpost

Seller: https://backpack.tf/profiles/76561198204063037#!/compare/1498003200/1498176000

Buyer: https://backpack.tf/profiles/76561198073607643#!/compare/1498003200/1498089600

X = 25

Sale 2:

Sold for Pro. KS Aussie Black Box (19) + 2 keys + Strange Pro. KS Family Business (2)

No outpost

Seller: https://backpack.tf/profiles/76561198072240925#!/compare/1499040000/1499126400

Buyer: https://backpack.tf/profiles/76561198256589823#!/compare/1499040000/1499126400

X = 23

Sale 3:

Sold for Kill-a-Watt Hot Dogger + Killstreak Aussie Axtinguisher (6)

http://www.tf2outpost.com/trade/29219719 - B/O of 25

Seller: https://backpack.tf/profiles/76561198050933686#!/compare/1496880000/1496966400

Buyer: https://backpack.tf/profiles/76561198288100148#!/compare/1496880000/1496966400

Will most likely cap, or at least fall in the range.

Sale 4:

Sold for Steaming Brown Bomber

No outpost

Seller: https://backpack.tf/profiles/76561198256589823#!/compare/1499126400/1499212800

Buyer: https://backpack.tf/profiles/76561198189133167#!/compare/1499126400/1499212800

Probably better to use on the Steaming one, given the lack of B/O here.

Sale 5:

Sold for Kill-a-Watt Front Runner + Conga

No outpost

Seller: https://backpack.tf/profiles/76561198170165201#!/compare/1499558400/1499990400

Buyer: https://backpack.tf/profiles/76561198269650829#!/compare/1499904000/1499990400

Front runner looks rather overpriced, may be better to use it on the front runner instead.

Sale 6:

Bulk for Miami Nights Brotherhood

Seller: https://backpack.tf/profiles/76561198189133167#!/compare/1499212800/1499299200

Buyer: https://backpack.tf/profiles/76561198168489289#!/compare/1499126400/1499299200

Sale 7:

Bulk for Orbiting Fire Crones

Seller: https://backpack.tf/profiles/76561198168489289#!/compare/1499126400/1499299200

Buyer: https://backpack.tf/profiles/76561198067397074#!/compare/1499126400/1499299200

Sellers:

24 keys:

http://i.imgur.com/CKtmKxq.png

27 keys:

http://i.imgur.com/HGaSOvs.png - 10 days

Sales at:

23

25

Another sale at 25 or less.

Going with 23-25.