Sale 1:

Sold for Morning Glory Front Runner* = 8 buds (no overpay since hat sold in pure)

http://www.tf2outpost.com/trade/25317464

http://i.imgur.com/Ur5XKl9.png

Sale 2: (invalid sale)

Involved in a bulk deal for a Poisoned Shadows Executioner

http://www.tf2outpost.com/trade/24115697

http://backpack.tf/profiles/76561198019710414?time=1421882115 → http://backpack.tf/profiles/76561198019710414?time=1421913600

Sale 3:

Sold for 3 buds + Australium Scattergun ([49.5/13]*0.9) = 3 + 3.34 = 6.34 (rounding to 6.3 buds)

http://www.tf2outpost.com/trade/24836698

http://backpack.tf/profiles/76561198072165163?time=1422685455 → http://backpack.tf/profiles/76561198072165163?time=1422691200

Sale 4:

Sold for Australium Scattergun ([44.5/12]*0.9) + 1 bud (1) + 46 keys (46/12) = 3.3375 + 1 + 3.8333 = 8.17 (rounding to 8.2 buds)

http://www.tf2outpost.com/trade/24890953

http://backpack.tf/profiles/76561198065713150?time=1424387453 → http://backpack.tf/profiles/76561198065713150?time=1424419200

Sale 5: (invalid sale, unpriced hat)

Sold for TF Logo Tipped Lid

http://www.tf2outpost.com/trade/25204897

http://backpack.tf/profiles/76561197974631996?time=1425536084 → http://backpack.tf/profiles/76561197974631996?time=1425542400

Sale 6: (invalid sale, unpriced hat)

Sold for Scorching Flames Belgian Detective

http://www.tf2outpost.com/trade/25301530

http://backpack.tf/profiles/76561198109369803?time=1425761929 → http://backpack.tf/profiles/76561198109369803?time=1425801600

Mini-suggestion for Morning Glory Front Runner*:

http://www.tf2outpost.com/trade/24823549 - Sold for 8 buds (only other sale apart from Sale 1)

http://www.tf2outpost.com/trade/24835712 - Had a collecting offer of 8 buds

~Valuing this at 8 buds.

Support-proof:

http://www.tf2outpost.com/trade/24890953 - Rejected offer of 7 buds

http://www.tf2outpost.com/trade/25204897 - Rejected offer of 90 keys (7.5 buds)

http://www.tf2outpost.com/trade/24890953 - Apparently been offered 8.5 buds

Notes:

For valuing the buds and Australiums, I'm using the price at the time of sale.

Due to the support-proofs provided, it indicates that anything below 7.5 buds is an outlier and thus, calling Sale 3 an outlier.

Conclusion:

Sales at 8, 6.3, 8.2 buds, along with the plenty of support-proof suggesting that this taunt is close to or even more than the 8 buds region.

Taking a final range of 8-8.2 buds.

Feel free to support/counter my suggestion!