Sale 1:

Sold for either a Dead President’s Connoisseur’s cap or a C9 Tin Gallon. Both of them are in-date, so this should cap at 12.

http://www.tf2outpost.com/trade/27942837 - B/O of 12

Seller: http://backpack.tf/profiles/76561198066195760#!/compare/1458284400/1458370800

Buyer: http://backpack.tf/profiles/76561198117750227#!/compare/1458370800/1458457200

I have no idea which of the two it sold for.

X = 12 (Capped by B/O)

Sale 2:

Sold for Blizzardy Storm Brigade Helm

http://www.tf2outpost.com/trade/28040645 - B/O of 12

Seller: http://backpack.tf/profiles/76561198042938501#!/compare/1459728000/1459814400

Buyer: http://backpack.tf/profiles/76561198170510086#!/compare/1459814400/1460073600

Sale should definitely cap at 12

X = 12 (Capped by B/O)

Sale 3:

Sold for 11 keys

http://www.tf2outpost.com/trade/28149778 - B/O of 11

Seller: http://backpack.tf/profiles/76561198001313309#!/compare/1462665600/1462838400

Buyer: http://backpack.tf/profiles/76561198025018960#!/compare/1462665600/1462838400

X = 11

Sale 4:

Sold for 10 keys?

http://www.tf2outpost.com/trade/27939142 - No B/O

Seller: http://backpack.tf/profiles/76561198057654162#!/compare/1458025200/1458111600

Buyer: http://backpack.tf/profiles/76561198042938501#!/compare/1458025200/1458111600

X = 10

Sale 5:

Sold in ~1 day for 9 keys + 3 ref

http://www.tf2outpost.com/trade/28149365 - B/O of 10

Seller: http://backpack.tf/profiles/76561198093829935#!/compare/1462665600/1462838400

Buyer: http://backpack.tf/profiles/76561198001313309#!/compare/1462579200/1462665600

X = 9

Sale 6:

Sold for 8 keys?

http://www.tf2outpost.com/trade/27986590 - B/O of 10

Seller: http://backpack.tf/profiles/76561198117750227#!/compare/1458630000/1458716400

Buyer: http://backpack.tf/profiles/76561198045354273#!/compare/1458630000/1458716400

Sale probably wasn’t 8, he was offered 9 by someone else.

Sale 7:

Sold for Dead Presidents Sultan’s Ceremonial

http://www.tf2outpost.com/trade/28147419 - B/O of 13, “Quicksell”

Seller: http://backpack.tf/profiles/76561198078306041#!/compare/1462492800/1462665600

Buyer: http://backpack.tf/profiles/76561198093829935#!/compare/1462492800/1462665600

Would rather have this sale be used to update the ceremonial. If it were used here, it would most likely fit in the range anyways (with a seller at 12 on the classifieds for a month)

Sellers:

11 keys:

http://puu.sh/oXznt/1e0394e208.png - 3 days

12 keys:

http://puu.sh/oXzp7/7b350920f7.png - 3 months

http://puu.sh/oXzpU/583b4e225f.png - 3 days

Offers:

http://www.tf2outpost.com/trade/28081477 - 1 month

http://www.tf2outpost.com/trade/28140134 - 1 week

Sales at:

12

12

11

10

9

8?

Buyers at 8, excluding 8

Sale at 9 happened pretty fast, and the seller in sale 6 declined 9 keys in his outpost trade. Going to exclude 9 (including it would also create a large range)

Going with 10-12