Underpriced, ye.

Offers/Solds at 3.33 ref or higher:

http://www.tf2outpost.com/trade/19703744 (Sold at 3.11)

http://www.tf2outpost.com/trade/19072907 (offer of 9 ref for 2 -4.49 each, 5.55 ref, 3.33 ref (x2), 3.55

http://www.tf2outpost.com/trade/19600960 (Sold at 3.33)

http://bazaar.tf/trade/800216 (Sold at 3.33)

http://www.tf2outpost.com/trade/19305784 (Rejected offers of 3 (x2) and 3.33)

http://www.tf2outpost.com/trade/19104689 (Offer of 6.66)

Quicksells at 3 ref:

http://www.tf2outpost.com/trade/19718257

http://www.tf2outpost.com/trade/19707729

http://www.tf2outpost.com/trade/19684606

For those who don't think there is enough proof, check op. Silver Rocket market is flooded with killstreaks or strange parts.

Thx :&)