Sale 1:

Sold for Cloud 9 Modest Metal Pile of Scrap (Mini at 29 below)

http://www.tf2outpost.com/trade/28819532 - B/O of 28

Seller: http://backpack.tf/profiles/76561198021055079#!/compare/1489795200/1489881600

Buyer: http://backpack.tf/profiles/76561198118656554#!/compare/1489622400/1489881600

http://imgur.com/a/cmElC

X = 28 (Capped by B/O)

Sale 2:

Sold for 23 keys

No outpost

Seller: http://backpack.tf/profiles/76561198108148076#!/compare/1487030400/1487116800

Buyer: http://backpack.tf/profiles/76561198315232265#!/compare/1487030400/1487116800

Seller confirms sale here:

http://backpack.tf/suggestion/58aa85e60e2cad67f330241d

X = 23

Sale 3:

Sold with 10+ keys in items for Circling Peace Sign Tossle Cap (27.5)

No outpost

Seller: http://backpack.tf/profiles/76561198315232265#!/compare/1488153600/1488412800

Buyer: http://backpack.tf/profiles/76561198021055079#!/compare/1488326400/1488412800

http://imgur.com/a/v2O4N

X = 17

Sale 4:

Sold with 30 keys? for Disco Beat Down Human Cannonball

Seller: http://backpack.tf/profiles/76561198118656554#!/compare/1489881600/1489968000

Buyer: http://backpack.tf/profiles/76561198080179568#!/compare/1489881600/1489968000

If this sale is correct, it would be too bulky to be used here.

Cloud 9 Modest Metal Pile of Scrap Mini:

Sale 1:

Sold with a key for Spellbound Electric Escorter (37)

http://www.tf2outpost.com/trade/28731225 - B/O of 30

Seller: http://backpack.tf/profiles/76561198080179568#!/compare/1485216000/1485302400

Buyer: http://backpack.tf/profiles/76561197993363628#!/compare/1485216000/1485388800

X = 30 (Capped by B/O)

Sale 2:

Sold for Disco Beat Down Outta Sight (Mini at 39 below)

http://www.tf2outpost.com/trade/28841570 - B/O of 30

Seller: http://backpack.tf/profiles/76561198021055079#!/compare/1490227200/1490313600

Buyer: http://backpack.tf/profiles/76561198177836546#!/compare/1490140800/1490313600

http://imgur.com/a/4yIqr

X = 30 (Capped by B/O)

Sale 3:

Sold for Abduction Universal Translator (Indate at 45, sellers at 37)

http://www.tf2outpost.com/trade/28831831 - B/O of 28

Seller: http://backpack.tf/profiles/76561198080179568#!/compare/1489449600/1489536000

Buyer: http://backpack.tf/profiles/76561198118656554#!/compare/1489449600/1489536000

X = 28 (Capped by B/O)

Going with 28-30 (29)

Disco Beat Down Outta Sight Mini:

http://backpack.tf/suggestion/58cf13730e2cad647e073c9d

Sellers:

15 keys:

http://www.tf2outpost.com/trade/28832090 - 1 week, 5 days unbumped. Unsure of the validity of this seller.

http://backpack.tf/item/5383983120

http://backpack.tf/profiles/76561198075688051

24 keys:

http://i.imgur.com/WGOYWDv.png - 7 days

http://backpack.tf/u/76561198080179568

http://www.tf2outpost.com/trade/28847513

Sales at:

17

23

28

17 seems like an outlier, as I've received offers at or better than this price (can provide proof of offers in a couple hours). That, and the bot dogger was offered to me.

Going with 23-28.