More Sales:

Sale 1) DBD Cannonball (42.5 Keys) + Blizzardy Cannonball (27 Keys) + 77 Refined (4 Keys) + 1 Key = 74.5 Keys, which would round to 75 Keys

http://backpack.tf/profiles/76561198137762264/#!/compare/1455782400/1455868800

The DBD Cannonball is currently Outdated, but was in date when the sale occurred, so 42.5 should be fine.

Sale 2) Sold for a Flaming Lantern Western Wear (34) + 5 Keys

http://backpack.tf/profiles/76561198048431762?time=1456560000

http://backpack.tf/vote/id/5712db8b8667472fd47d0dec - Western Wear is 34 Keys

Sale 3) Sold for a Professional Killstreak Australium Scattergun + Cloud 9 Human Cannonball

http://backpack.tf/profiles/76561198080179568/#!/compare/1459209600/1459296000

http://www.tf2outpost.com/trade/28007236 - Capped by the Buyout of 70 Keys

Sale 4) Sold for a Max's (29.5) + Terror-Watt Dread Knot + Strange Spec KS Backwoods Boomstick (~2) + an Unusual SMG

http://backpack.tf/profiles/76561198136099561/#!/compare/1456473600/1457078400

http://www.tf2outpost.com/trade/27918226 - Likely capped by the Buyout of 55 Keys

Sale 5) Sold for 72 Keys

http://backpack.tf/profiles/76561198067902503/#!/compare/1455955200/1456214400

Sale 6) Quicksold for 58 Keys

http://backpack.tf/profiles/76561198120505232/#!/compare/1454400000/1455091200

Sale 7) Sold for 60 Keys

http://backpack.tf/profiles/76561198240000948/#!/compare/1458370800/1458457200

Sale 8) Both of your sales are the same exact sale. It was 90 Keys, not 60

http://www.tf2outpost.com/trade/27970399 - See the Buyer's comment

Summary

39

55

58 Pure Quicksell

60 Pure

70

72 Pure

75

90 Pure

39 and 55 Keys are Outliers because of the 58 Key Quicksell, and I'd say 90 is an Outlier for being so far away from the other sales.

Since 72 Keys took 7 Days, I'd say 60 Keys is an Outlier as well.

70 - 75 would be a better range here.