[Proof below] - 5 months old price, let's update this Space Pirate! Thanks to Ramses for helping me find the old sales.

Overpay is calculated

Active Trades

http://www.tf2outpost.com/trade/13168961 - 5 hours

B/O 1 bud + 5 keys

Current offers (coming from his plethora of other trades):

1 bud

Vivid Plasma Dread Knot + 2 keys + craft hat = ~ 1 bud

Steaming Connoisseur's Cap = ~ 19 keys

Bubbling DeGroot Experience = ~ 1 bud

Smoking Big Elfin' Deal, Bootie Time, Strange Wrap Assassin (hats painted gold) + Festive Scattergun = ~ 17 keys

http://www.tf2outpost.com/trade/13147969 - 22 hours

B/O 1 bud + 2 keys, no offers.

http://www.tf2outpost.com/trade/13141288 - 1 day (poorly bumped?)

B/O 1 bud + 2/3 keys, no offers.

http://www.tf2outpost.com/trade/13094491 - 2 days (poorly bumped?)

B/O 1 bud (22 keys), no offers.

http://www.tf2outpost.com/trade/13067010

B/O 1 bud (1.4 in unusuals), only had offers on both hats as a set.

http://www.tf2outpost.com/trade/12774018 - 1 week

B/O 24 keys or equivalent in other currencies.

Declined offers:

1 bud

Steaming Connoisseur's Cap = ~ 19 keys

http://www.tf2outpost.com/trade/12792701 - 1 week

B/O None

Highest offer:

1 bud (retracted)

http://www.tf2outpost.com/trade/12810352 - 1 week

B/O 2 buds, no offers.

http://www.tf2outpost.com/trade/12233360 - 3 months

B/O None

Declined/retracted offers:

Steaming Barnsotmer = ~ 1.1 buds

Circling TF Logo Nanobalaclava = ~ 1.1 buds

Blizzardy Storm Bucket Helm = ~ 1 bud

Steaming Connoisseur's Cap = ~ 19 keys <---- this guy is everywhere! o.O

http://www.tf2outpost.com/trade/8403830 - 5 months

B/O 1 bud + 5 keys, was offered 1 bud + 10 keys a while back but this didn't go through, buyout has presumably been lowered.

Declined/retracted offers:

1 bud

Orbiting Planets Samur-eye = ~ 1 bud

Orbiting Planets Big Country + 8 keys = ~ 1 bud

Smoking Big Elfin' Deal + Bootie Time = ~ 14 keys

Outlier: http://www.tf2outpost.com/trade/11856887 - 1 month

B/O 3 buds, no offers.

Sales

http://www.tf2outpost.com/trade/12787711 - For S.Festive Sticky w/ strange parts = ~ 1 bud - http://www.tf2outpost.com/trade/12908128

http://www.tf2outpost.com/trade/12079588 - For http://www.tf2outpost.com/trade/12080250 = ~ 1 bud

So we can concluded that there have been sales at 1 bud but also some rejected offers at 1 bud (22 keys) along with 1.1 bud (24 keys) offers, so a range of 1-1.1 fits best.