Maybe you would be willing to do another of your cost analyses for us: How much must I spend on DP in order to feel that my prints really are worth every penny I spend on ink and paper as well as initial printer cost? How much more DP will it take for me to feel justified in junking my lowly 2200 and getting a 7800? I think those are the key economic questions we should be dealing with.
Eric, indeed, if possible it could make a significant contribution to the literature; but I fear there are critical data gaps to deal with. You see, it is a dynamic, non-linear problem, because there are discontinuities in cause and effect that are distributed in real time and probably asymetric (e.g. how much antidote for the front end-investment versus how much antidote for the supplies thereafter, at what cyclicality and volumes over what time period, and what discount rate for deriving present values). Unfortunately, we don't have a data base of tested cases from which to draw inferences for other consumers (i.e. Alain already has his x800 printer and consumed the DP, but probably didn't record the existential relationship between the two at the time.) Then to complicate the matter further, borrowing from the field of environmental science, you would probably need a "cumulative impacts analysis" to get it right, because the effect of alcohol on the brain works that way. My goodness, nothing like lawyers, tax accountants and economists to complicate life for us, isn't it? Better to be a humble drunken photographer, charge enough money for the prints to pay for the bl..dy ink and be done with it!