I bought the Collector's Edition (English) from a UK seller on Ebay. It was new and sealed, but only came with the walkthrough booklet and soundtrack CD. There was no Poster or anything else.
If the only thing you're missing is the poster and the discs actually work then you should consider yourself lucky! There were problems with the Lace Mambe "Collector's Edition" right out of the starting gate (see
this thread).
Coincident to your query,
this was just posted today on the Amanita Design Facebook page regarding Lace Mamba:
"I've just read this sad articla about UK publisher Lace Mamba and must say that we have the exact same experience. Lace Mamba released boxed version of Machinarium and since then they don't pay and communicate. And not only with us but probably with every game developer who signed the deal with them (Daedalic, Colibri Games, CBE and others). Please don't buy anything from this company!"
link:
http://indiestatik.com/2013/01/25/never-paid-us-a-single-cent-lace-mamba-global-breach-publishing-deal-with-cbe-software/As for your poster, stove, I wouldn't be surprised if Amanita Design eventually added such an item to their
store. Be patient. (the ultimate answer to all our desires, eh? ;~)