The Fruit Ninja sword!!!!!!! Proof:

Sellers bellow current range:

http://www.tf2outpost.com/trade/20861061 - 1 key 3 ref

http://www.tf2outpost.com/trade/20851074 - 1 key 3 ref

Unsolds at 2 keys:

http://www.tf2outpost.com/trade/20910364 - young

http://www.tf2outpost.com/trade/20041346 - 1 month (was proof on the previous suggestion)

http://www.tf2outpost.com/trade/20790553 - 4 days

http://www.tf2outpost.com/trade/20769109 - 5 days

Solds:

http://www.tf2outpost.com/trade/20780193 - sold for 1 key 5 ref

http://www.tf2outpost.com/trade/20112422 - sold for 1 key 5 ref

Conclusion: Not a lot of fruit ninjas. Less than a page of sellers, some are untradeable and in a set as well. Two sellers at 1 key 3 ref thus lowering the range to 1.35 keys, solds at 1.6 so keeping that there and unsolds at 2 thus needing to be excluded from the range.