Main Sales:

SOLD for 73 keys = 4.2 buds

http://backpack.tf/profiles/76561198013031193?time=1404025200 -> http://backpack.tf/profiles/76561198013031193?time=1404198000

Sold for a duped burning bucket = 4.1 buds

http://backpack.tf/profiles/76561198023881713?time=1402729200 -> http://backpack.tf/profiles/76561198023881713?time=1402815600

Sold for a DBD tower = 5.5 buds

http://backpack.tf/profiles/76561198043674551?time=1403161200 -> http://backpack.tf/profiles/76561198043674551?time=1403247600

Some other sales:

http://www.tf2outpost.com/trade/20139402

Offered for a PE Fruit shoot = 3.5-4 maybe, but calling this an outlier due to this guy's desire for a fruit shoot: http://www.tf2outpost.com/trade/20335862

(yeah, I know. So HE'S the one!)

http://www.tf2outpost.com/trade/20965224 (most recent)

Offered for a steam TC + 5 keys (spoke to the TC owner) = ~4 buds

TC is outdated, current B/Os are 4 buds tho and TCs are pretty stable.

http://www.tf2outpost.com/trade/20735492

Offered for a DBD casemaker (unpriced)

Current trades:

http://www.tf2outpost.com/trade/19441597 B/O 5 buds

http://www.tf2outpost.com/trade/20959379 B/O 5 buds

3 others have 6 bud B/Os

So using the 4-5 range based on the couple sales of 4-5.5, but cutting the top off at 5 based on current B/Os not to mention the 5.5 is DBD so using a 3rd gen to price a 3rd gen isn't the most reliable.