Digital BW, The Print

Hi group,

I'm curious how members on this list may price themselves on the
commercial market for the prints they are making. I've seen several ways
of doing this, from a listing of sizes and related charges, to a per
square inch formula. 

How do you differentiate between a smaller size print (11x14), that
takes just as much time to print as a large one. Perhaps a set-up fee to
begin the process, and what about a proof first for larger size prints...

what is a fair price to charge a customer for a 24" x 28" print on
archival paper and using MIS inks? 

what is a fair price to charge for a 30 x 40 or 40 x 60?

thanks for any input...

Mark MacKinnon
320studio