About 15 sellers for 11 on classified:

http://backpack.tf/classifieds/?item=Dead%20Ringer&quality=11&tradable=1&craftable=1

Sellers:

http://www.tf2outpost.com/trade/24717844 (11 ref)

http://www.tf2outpost.com/trade/24355862 (10 ref bot)

http://www.tf2outpost.com/trade/24711131 (11 ref)

http://www.tf2outpost.com/trade/24706352 (11 ref)

http://www.tf2outpost.com/trade/24719205 (11 ref)

http://www.tf2outpost.com/trade/24668627 (11 ref)

Unsolds at 12 ref:

http://www.tf2outpost.com/trade/24585587 (1 week)

http://www.tf2outpost.com/trade/24665371 ( 3 days)

http://www.tf2outpost.com/trade/24712732 (1 day)

http://www.tf2outpost.com/trade/24694873 (1 day)

http://www.tf2outpost.com/trade/24378981 (2 weeks)

http://www.tf2outpost.com/trade/24699015 (1 day)

http://www.tf2outpost.com/trade/24357839 (3 weeks poorly bumped)

http://www.tf2outpost.com/trade/24685166 (2 days)

http://www.tf2outpost.com/trade/24372826 (2 weeks)

http://www.tf2outpost.com/trade/24479700 (2 weeks)

http://www.tf2outpost.com/trade/24707074 (1 day)

http://www.tf2outpost.com/trade/24025175 (1 month poorly bumped)

http://www.tf2outpost.com/trade/24539773 (1 week)

http://www.tf2outpost.com/trade/24596787 (11.88 1 week)

http://www.tf2outpost.com/trade/24329935 (3 weeks poorly bumped)

http://www.tf2outpost.com/trade/24702122 (1 day poorly bumped)

http://www.tf2outpost.com/trade/24449542 (2 weeks poorly bumped)

Add on if you want