>>The discussion of the value of an original vs reproductions is also very important, but might be a slightly different point IMHO.<<
One question is, "What's an original?" With digital reproduction, it's possible to essentially make as many "originals" as you want, as there is no detectable difference between the copies. That's not true either with wet darkrooms or painting. I have a modest collection of photos, and I can tell you that before each purchase there is always a discussion of whether the print "is a good one." Is it a good Moonrise or a good Running White Deer, or is it a slightly-off version?
Then, in something that has nothing to do with aesthetics, a lot of well-known photographers have begun editioning their prints, to make them artificially scarce. This actually works; I own a one-of-nine Mapplethorpe flower print, and every year or so the dealer I bought it from (in '94 or so) calls me up to see if I want to sell it, because they have become extremely hard to get. But Mapplethorpe could have made a thousand prints of the same picture, and it wouldn't have diminished my experience of the print at all; but if he had, I can guarantee that nobody would be calling me up.
If we lived in a particular kind of non-human society where nobody had the snob impulse, then the best photographers would make hundreds of their prints available at modest prices, and everybody would be satisifed by the purely aesthetic experience, and the artist would make as much money as they do now with a liimited edition. But, one-upmanship is purely human, so here we are, buying limited editions.
Here's an idea for the ultimate modern aesthetic experience: make ONE copy of a great photo, have it shown in a good museum, then get a picture of yourself burning it, and sell a limited edition those pictures. Hmmm...now if I could just make one great photo...