My second suggestion now, feel free to criticize!

Selling:

Unsold at 3 Keys

http://www.tf2outpost.com/trade/11622900 (2 weeks)

http://www.tf2outpost.com/trade/11615188 (2 weeks)

http://www.tf2outpost.com/trade/11947756 (1 week)

http://www.tf2outpost.com/trade/11806460 (1 week)

http://www.tf2outpost.com/trade/12006593 (6 days)

http://www.tf2outpost.com/trade/12027011 (6 days)

http://www.tf2outpost.com/trade/12051094 (5 days)

http://www.tf2outpost.com/trade/12038253 (4 days, now selling for 2 keys + 2 ref)

http://www.tf2outpost.com/trade/12184522 (1 day)

http://www.tf2outpost.com/trade/12187013 (23 hours)

http://www.tf2outpost.com/trade/12187217 (22 hours)

http://www.tf2outpost.com/trade/12203388 (13 hours)

Classifieds: http://i.imgur.com/n4Jxlqp.png (6, 4 and 2 days)

Unsold at 2.8 keys

http://www.tf2outpost.com/trade/11981872 (1 week)

http://www.tf2outpost.com/trade/11902323 (1 week)

http://www.tf2outpost.com/trade/12002488 (6 days)

http://www.tf2outpost.com/trade/12092222 (3 days)

http://www.tf2outpost.com/trade/12102642 (3 days)

Unsold at less than 2.8 keys

http://www.tf2outpost.com/trade/12102466 (2.4 keys, 3 days)

http://www.tf2outpost.com/trade/12172898 (2.4 keys, 3 days, mentioned above)

Buying:

Highest buyer on TF2OP: http://www.tf2outpost.com/trade/10880595 (2.2 keys)

has an offer of 2 keys + 2.33 ref, but has hidden it.

Another buyer (http://www.tf2outpost.com/trade/10252579) has an offer of 2 keys + 3.66 ref, but has not responded yet.

In addition: http://www.tf2outpost.com/trade/11920915 (1 week, no offers)

All in all, it looks like it's not that much of a wanted Strange/BK.