Difference between US (mtgstocks) and EU(MCM) prices

I'm confused by the prices of EU vs US.
I've got a playset of Aven Mindcensor on MCM and saw they were dropping almost a euro since last month, where as on MTGstocks they have risen a dollar since then.

I've noticed that in general MCM prices lag behind a bit, is this the december drop of US that is now happening on MCM?