Sale 1:

Sold for Bubbling Cloud Crasher (13) + 5 keys

No outpost

Seller: https://backpack.tf/profiles/76561198156255538#!/compare/1503446400/1503532800

Buyer: https://backpack.tf/profiles/76561198114141445#!/compare/1503532800/1503792000

X = 18

Sale 2:

Sold with a ref for Stormy Storm L’inspecteur (12.5) + 5 keys

No outpost

Seller: https://backpack.tf/profiles/76561198073618741#!/compare/1500163200/1500249600

Buyer: https://backpack.tf/profiles/76561198184211331#!/compare/1499904000/1500249600

X = 17

Sale 3:

Sold with 1 key for Smoking Human Cannonball (18)

No outpost

Seller: https://backpack.tf/profiles/76561198240511506#!/compare/1501113600/1501372800

Buyer: https://backpack.tf/profiles/76561198267189538#!/compare/1501286400/1501372800

X = 17

Sale 4:

Sold for 16 keys

No outpost

Seller: https://backpack.tf/profiles/76561198060146051#!/compare/1500336000/1500508800

Buyer: https://backpack.tf/profiles/76561198161496270#!/compare/1499904000/1500595200

X = 16

Sale 5:

Sold for Kill-a-Watt Tricorne (14.5) + 1 key + ~0.5 keys in items

No outpost

Seller: https://backpack.tf/profiles/76561198059769005#!/compare/1503100800/1503187200

Buyer: https://backpack.tf/profiles/76561198174203179#!/compare/1503100800/1503187200

X = 16

Sale 6:

Sold for Miami Nights Coupe D’isaster (Suggestion at 11) + 4 keys + Mannrobics + 20 ref (~2 keys together)

http://www.tf2outpost.com/trade/29308968 - B/O of 17

Seller: https://backpack.tf/profiles/76561198131555957#!/compare/1501632000/1501718400

Buyer: https://backpack.tf/profiles/76561198326093863#!/compare/1501632000/1501718400

X = 16

Sale 7:

Sold for Smoking Large Luchadore (11) + 4 keys

http://www.tf2outpost.com/trade/29281043 - B/O of 18

Seller: https://backpack.tf/profiles/76561198184211331#!/compare/1503705600/1503792000

Buyer: https://backpack.tf/profiles/76561198269636307#!/compare/1503705600/1503792000

X = 15

Sale 8:

Sold for 15 keys

No outpost

Seller: https://backpack.tf/profiles/76561198344933095#!/compare/1499904000/1499990400

Buyer: https://backpack.tf/profiles/76561198060146051#!/compare/1499904000/1499990400

X = 15

Sale 9:

Quicksold for 14 keys

No B/Os on Outpost

Seller: https://backpack.tf/profiles/76561198267189538#!/compare/1501545600/1501632000

Buyer: https://backpack.tf/profiles/76561198097138683#!/compare/1501545600/1501632000

X = 14

Sale 10:

Quicksold for 14 keys

http://www.tf2outpost.com/trade/29269310 - B/O of 14, lowered from 17:

http://www.tf2outpost.com/trade/29266551 Sold in about a day after lowering to 14.

Seller: https://backpack.tf/profiles/76561198107520045#!/compare/1499731200/1499817600

Buyer: https://backpack.tf/profiles/76561198160089663#!/compare/1499731200/1499817600

X = 14

Sale 11:

Sold for Spec. KS Aussie Tomislav (12) + ~2 keys in items

http://www.tf2outpost.com/trade/29349502 - B/O of 14

Seller: https://backpack.tf/profiles/76561198326093863#!/compare/1501977600/1502064000

Buyer: https://backpack.tf/profiles/76561198074560443#!/compare/1501977600/1502064000

X = 14

Sale 12:

Quicksold for 12 keys + ~1 key in ref

No outpost

Seller: https://backpack.tf/profiles/76561198314349856#!/compare/1500163200/1500249600

Buyer: https://backpack.tf/profiles/76561198073618741#!/compare/1500163200/1500249600

X = 13

Sale 13:

Bulk for Grail Rancho

Seller: https://backpack.tf/profiles/76561198074560443#!/compare/1502409600/1502496000

Buyer: https://backpack.tf/profiles/76561198078938863#!/compare/1502409600/1502496000

Sale 14:

Sold with 4 keys for Neutron Star Nasty Norsemann

Seller: https://backpack.tf/profiles/76561198112939394#!/compare/1501113600/1501286400

Buyer: https://backpack.tf/profiles/76561198156255538#!/compare/1501200000/1501286400

Would be better to use this on the Norsemann.

Miami Coupe:

https://backpack.tf/suggestion/59a80c96cf6c75310b757460

Sellers:

17 keys:

http://i.imgur.com/ZJayvr8.jpg - 2 days

18 keys:

http://i.imgur.com/0kRu76K.png - 11 days

20 keys:

http://i.imgur.com/usl7B11.png - 4 months

Sales at:

13

14 (3x)

15 (2x)

16 (3x)

17 (2x)

18

14 quicksold. Excluding 13 and 14.

Going with 15-18.