For practical purposes, I think this is a decision that most people let the market make, i.e.--when a gallery says "we only represent photographers who make limited editions" and you want to get into that gallery, you decide to limit editions. One might ask how much of a limitation this is, since I suspect that few editions of 100 or more get past the fifth print, and most people probably want to move on after the 100th print of any image.