9 months old price!

Sale 1:

Sold for 3 buds + 4 keys (4/13) + Sweets (~0.1) = 3 + 0.3 + 0.1 = 3.4

http://www.tf2outpost.com/trade/24327836

http://backpack.tf/profiles/76561198001311391?time=1419667200 → http://backpack.tf/profiles/76561198001311391?time=1419753600

Sale 2:

Sold for 30 keys (30/11.25) = 2.67 (rounding to 2.7)

http://www.tf2outpost.com/trade/24166328

http://backpack.tf/profiles/76561198052422739?time=1419148800 → http://backpack.tf/profiles/76561198052422739?time=1419235200

Sale 3:

Sold for 43 keys (43/13) = 3.31 (rounding to 3.3)

http://backpack.tf/profiles/76561198067910800?time=1417852800 → http://backpack.tf/profiles/76561198067910800?time=1418025600

Sale 4: (invalid sale)

Sold for CS:GO items

http://www.tf2outpost.com/trade/24045295

Sale 5: (invalid sale, outdated hat)

Sold for Stormy Anger (2.9*0.9) = 2.61 (rounding to 2.6)

http://www.tf2outpost.com/trade/24076862

Notes:

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

http://www.tf2outpost.com/trade/24584138 - B/O of 3 buds

http://www.tf2outpost.com/trade/24076862 - B/O of 3.5 buds

I included the approximate value of Sale 5 just as support-proof for Sale 3.

Conclusion:

Sales at 2.7, 3.3, 3.4, and an unused sale at 2.6. Valuing final range at 2.7-3.4 buds.

Feel free to support/counter my suggestion!

(credits to polar for proof of some sales)