Proof below. 3 month-old price.

Sales:

http://www.tf2outpost.com/trade/16243073

-b/o of 4 buds

-sold for 3 buds pretty quickly: http://www.tf2outpost.com/trade/16246672

http://www.tf2outpost.com/trade/15622697

-sold for duped v. medal+6 keys=4.2 buds, outlier and anyway medal is probably worth less

http://www.tf2outpost.com/trade/15523546

-wanted 3 buds

-sold for 3 buds, took a few days, look here for proof: http://backpack.tf/vote/id/52a801504dd7b80e7e8b4568

http://www.tf2outpost.com/trade/14980389

-'quickselling' for ~3.2 buds

-seems to have sold for 55 keys=3.2 buds (bp history unclear)

http://www.tf2outpost.com/trade/15333972

-'quickselling' for ~3 buds

-sold for kaw drill (unpriced)=~3?

http://www.tf2outpost.com/trade/15688152

-b/o of 4 buds

-stash+p. fetti beak (4.65) bought scorching lid (8.15 outdated): http://www.tf2outpost.com/trade/14922334

-3.5 buds, no overpay as offered

http://www.tf2outpost.com/trade/15573937

-wanted 3 buds

-sold for 3 buds after 3 days

-seller's bp:

http://backpack.tf/id/76561198057487960?time=1384156800

http://backpack.tf/id/76561198057487960?time=1384243200

http://www.tf2outpost.com/trade/15554953

-b/o of 3.5 buds

-stash+p. fetti bonnet (0.85)+p. fetti panama (0.95)+3 buds bought beams baker (6.25): http://www.tf2outpost.com/trade/15513766

-seller's bp:

http://backpack.tf/id/76561198057487960?time=1383811200

http://backpack.tf/id/76561198057487960?time=1383897600

-1.5 buds, clear outlier

http://www.tf2outpost.com/trade/15611285

-sold for max+13 keys=~3 buds

http://www.tf2outpost.com/trade/15471603

-b/o of 3.5 buds

-sold for planets brainiac+sweets: http://www.tf2outpost.com/trade/15606165

-buyer's bp:

http://backpack.tf/id/76561198044618925?time=1383375600

http://backpack.tf/id/76561198044618925?time=1383462000

-~3.3 buds

Current trades:

http://www.tf2outpost.com/trade/15690935

-wants 5 buds, 1 month

-notable offers:

pe lid=2.9

cauldron pot=3

http://www.tf2outpost.com/trade/16045843

-wants 4.5 buds, 2 weeks

-notable offers:

ks ushanka (super outdated but last failed suggestion shows this is 2.7-3 before overpay)+10 keys=3.1

sulph fr-0=4.3 outlier

electrostatic strontium (unpriced)=~3?

http://www.tf2outpost.com/trade/15994080

-in a green+purple fetti set

http://www.tf2outpost.com/trade/16300402

http://www.tf2outpost.com/trade/16246076

-b/o of 4 buds

Sales: 1.5, 3, 3, 3, 3, 3.2, 3.3, 3.5, 4.2

Low end is pretty obvious at 3, looks like this is the borderline sellers want to sell at. For the high end I'm not using the 3.5 sale with an outdated unusual price as the only piece of proof to support it, so 3.3. Very close anyway. Unusual overpay and original prices used.