Editions and non-unique art objects

Erik's got an interesting post about editioned works (as many photogaphs are sold) over at "View from the Edge...", specifically about the effects of editions that get "broken", that is when the edition limit is subsequently expanded or a new edition of a work is created in a different size. The whole area of price setting in the arts is fascinating to me. I'd have to do a little research on pricing trends (actually, a lot of research), but I believe broken editions probably have limited impact on the long term value of previously sold editions. It's possible that the very fact that an edition is broken proves the popularity of the work and artist, resulting in an increase in market value for the original production run. Of course, none of this affects the intrinsic artistic value of the piece.