Valve will release a strangifier for this as it's duck related.

Classifieds at time of posting:

Sellers:

X1 at 12 refined (Not bumped in 3 days, supports nonetheless)

X1 at 12.66

X1 at 13 refined

X2 at 1 key

Buyers:

X3 at 10.44

X2 at 10.33

Proof: http://i.imgur.com/iecmNtK.jpg

Sellers at 10:

None, ayy

SOLDS at 12:

http://i.imgur.com/jx7KXgr.jpg

12 should do here. 12 sold fairly fast and no one is selling below 12, ruling them quickbuyers.