Guistik, please don't take it as an offense, but this question perfectly illustrates how we have difficulties translate our way of thinking into situations we haven't lived.
I guess those photographers have big difficulties getting normal photographic paper, and even if they could afford direct positive paper (even we in civilised countries would think twice, did you look at the price difference between normal paper and positive paper?) and even if they clients could afford paying for it they will still have the problem that the material is not avaible. Do you think they would work on paper if they could get at least film? (Btw, the photographers in Romania I talked about used sheet film in their cameras if I remember correctly, although I'm not shure.)
I take no offense, I was just wondering because it would seem to me that doing two exposures would be equal to the cost of just one with direct positive paper. I understand using paper as opposed to film because it is easier and quicker out in the streets. I just received a lens from a member here and plan on building one of these cameras around it, I think it is fascinating.
Thy heart -- thy heart! -- I wake and sigh,
And sleep to dream till day
Of the truth that gold can never buy
Of the bawbles that it may.