Proof below.

No known accepted suggestion for this, last and only suggestion (closed) was 9 months ago.

Sales:

http://www.tf2outpost.com/trade/15153322

-seems to have bought sf sticky+sf grenade with nice parts here: http://www.tf2outpost.com/trade/15174921

-~2.1 buds, no overpay

http://www.tf2outpost.com/trade/15019758

-wanted bp.tf price (1.6-2.1 buds?)

-sold for ~1.9 buds

-seller's bp:

http://backpack.tf/id/76561198022902098?time=1381993200 fez+99 keys

http://backpack.tf/id/76561198022902098?time=1382079600 131 keys

-1 bud involved: http://www.tf2outpost.com/item/440,2011404909 (sold it for keys)

-offers: o.f. milkman (1.5 outdated, rejected?), 1.3 buds (rejected)

http://www.tf2outpost.com/trade/14981879

-wanted 1.6 buds

-sold for 25 keys=~1.5 buds

-buyer's bp: http://backpack.tf/id/76561198022902098?time=1381561200 76 keys

http://backpack.tf/id/76561198022902098?time=1381647600 fez+51 keys

http://www.tf2outpost.com/trade/14810028

-seems to have added 1 bud to buy gifted stormy bomber (his price was 3 buds): http://www.tf2outpost.com/trade/14977508

-2 buds?

Current trades:

http://www.tf2outpost.com/trade/15186043

-wants 2 buds

http://www.tf2outpost.com/trade/15041034

-b/o of 2 buds

Sales: 1.5, 1.9, 2, 2.1

Very few notable offers, so I have only listed down a few. Since both current trades have b/os of 2 buds, I'll have to bring the sale down to 2 buds. With ~2 sales at 2 buds, that will be the high end, while the low end is the 1.5 bud sale.