I've started to sell of the spare from my Munchkin collection.
To start with I have sold a black die, and I'm now selling a set of promo dice in the colours red, white and blue. ( see
http://www.ebay.com/itm/262181585240 ).
Once I have enough confidence in eCommerce I will start selling the big stuff: At least one Heart of the Anomaly, several Sammlerkoffers, two sammlerboxes ( one still shrink wrapped ), Munchkin Water, a Munchkin Cookie and a Clerrical Errata.