The price is out of date and this is falling etc.

Unsold for 2 keys

http://www.tf2outpost.com/trade/7364770 - Unsold for 2 keys

Unsold for 1.5 keys

http://www.tf2outpost.com/trade/7474908 - Unsold for 5 ref

http://www.tf2outpost.com/trade/7586489 - Unsold for 5 ref

http://www.tf2outpost.com/trade/7593141 - Unsold for 1.5 keys

Sold/Selling for 1 key

http://www.tf2outpost.com/trade/7525058 - Sold for 1 key

http://www.tf2outpost.com/trade/7455375 - Sold for 1 key

http://www.tf2outpost.com/trade/7612566 - Selling for 1 key

http://www.tf2outpost.com/trade/7640276 - Selling for 1 key

http://www.tf2outpost.com/trade/7645543 - Selling for 1 key

This has fallen substantially, and it would not surprise me if it has further to fall in the future. Definitely not 1.5 - 2 keys.