Thanks for the advice.
I was trying to compare in terms of speed, but i realised i was not really specific, although I had to build about 10 pieces, which were then changed mid way. I am quite fast, as they do not require super realism, although it sucks doing poor models once one is accustom to doing 80% detailed models.
I think the difficult aspect is trying to educate them in how long something takes, including re-rendering because the material color used, makes the whole thing look terrible, which somehow they think its the rendered images fault.
I suppose there isnt a concrete answer, it could be a week to two weeks.
Here is a good comment, what are you doing just sitting there , I am rendering........