This is my first price suggestion so give me some advice :)

Sold for 3 key

http://www.tf2outpost.com/trade/9801273 price 3keys {sold2} (3 week old trade)

http://www.tf2outpost.com/trade/8902588 price 3 keys {sold 75} (1 month old trade)

http://www.tf2outpost.com/trade/8418527 price 3 keys ( 2month old trade)

http://www.tf2outpost.com/trade/8226732 price 3 keys (2month old trade)[offer 2 day ago for sinister for 1 key and 2 ts = 1.5+1.5+1 = 4 keys]

http://www.tf2outpost.com/trade/8481259 price 3 keys (2month old trade)

http://www.tf2outpost.com/trade/8367080 price 3 keys (pure) [offer 6 lime for 2 so 3 per 1]

sold out over 4 key

http://www.tf2outpost.com/trade/9836629 price 4 key [sold out] (2 weeks old trade)

need some price update because it 21 days old in price and no sell it for 2.5 key anymore most are selling it for 3 keys+

I dont want to put the up limit to 3.5 because i hardly see any sold for 3.5