Here's some more sales:

http://backpack.tf/profiles/76561198016042113?time=1445583600 (October 23rd)

http://backpack.tf/profiles/76561198016042113?time=1445670000 (October 24th)

http://www.tf2outpost.com/trade/26861534 - sold for *deep breath*:

N&B Brainiac (39.5)

G. Fetti Glengarry (20)

~1 key of skins

~36 keys of stranges

~1 key of vintages

~2 ref of haunteds

9 keys pure

~1 key of taunts

~2.5 keys of festives

~7 keys of sweets

Total sale value = (108 * 0.9 = 97.2) + 9 = 106.2, rounding to 105 keys

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http://backpack.tf/profiles/76561198048571227?time=1445410800 (October 21st)

http://backpack.tf/profiles/76561198048571227?time=1445497200 (October 22nd)

[no OP trade] - sold for Secret Private Eye? can't see the sale from buyer's perspective. best to ignore, doesn't add up.

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http://backpack.tf/profiles/76561198036591954?time=1444287600 (October 8th)

http://backpack.tf/profiles/76561198036591954?time=1444374000 (October 9th)

http://www.tf2outpost.com/trade/27194629 - sold with ~4 keys of sweets for D@D Bicorne (80 * 0.9 = 72) - 4 = 68 keys

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http://backpack.tf/profiles/76561198129285937?time=1444201200 (October 7th)

http://backpack.tf/profiles/76561198129285937?time=1444287600 (October 8th)

http://www.tf2outpost.com/trade/27188960 - sold for pro. collector's festive crossbow (40)? very low it seems

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So we've got sales at ~40(?), 44, 67, 68, 105. Taking 67-68 is probably best here, there's a bit of uncertainty with the 40 sale, and 105 is a huge outlier. So 67 flat is really close enough - upvote.