WOW, another one of those questions that confuses me! I own a lot of printers and do a a large volume of printing daily with a variety of printers and we did do some cost analysis several years back to see what prints were costing us; We print color high-resolution 3D images produced by CAD based software and I wanted to see which printer to buy. We started out using Epson printers because they were the best, but then we started using Canon printers for all the prints because of their superior speed. However we were having clients call and say "My prints faded and I wanted to keep them" so we would use our Epson printers which was not having that problem, soon we will use 100% Epson because they are getting faster. I will have to check my records but I believe an 8x10 was costing us about .55 at the time for ink and paper, that number sticks out but the darn 11 x 17 and 12 x 18 I don't remember, but it was "cheap".
Now, the question, do photographers really care about the cost of the ink and paper when making prints? I must admit for my hobby of photography I don't give a damn about the cost of the ink / paper because it's always been substantially cheaper for me to print my own than to have a professional company do it. I remember checking the cost of 8 x 10 prints using an Epson 1280 using Epson glossy photo paper and I think it was about .55.
If you sell a print for $50.00 or $100.00 does it matter if the print is $5.00 or $10.00?