Well, Michael, it may not matter if it takes me longer. I understand that this is an individual pursuit and that this thread is really only about a ballpark guess. That's fine with me and I am grateful for your input.
My thought is related to a value-judgement about how much a good print is worth and how to account for time-spent in the final ledger. If I want to sell a print, and I don't want to come up short or over-sell, then I need to know how to compare my time with some type of average.