Wil - I just see people adding their own experience to your posts. You did a fair amount of work to do your calculations and they do add to the general knowledge of the forum. I don't see the other participans shooting you down!
I would suggest that the cost of cutting three 4x6 sheets from an 8.5x11 as opposed to paying slightly less than 5 cents per precut sheet iis so close as to be negligable - similar to your analysis of the actual printing cost of two inks, the bulk cost of which is a difference of two times. The ink MIS sells, Image Speicalist, is also available from Precision Colors at a much better price, which brings the bulk cost of these inks closer to each other.
On my printers I print nearly all borderless photos. I haven't run into the dreaded waste ink full message yet. The little bit of overspray is conveniently collected in the foam area under the printhead path and doesn't harm the printer at all. Putting a stack of 4x6 sheets (Kirkland Costco paper precut) in the printer to do a big run of prints without the need to cut any paper is too convenient for me to do otherwise. I have, on rare occasion, had the trailing edge of a print with a bit of banding, and you do have to allow for a little bit of cropping which slightly reduces the image size, but the convenience is of more benefit to me than the chore of cutting any paper at all. My first inkjet printer, about 12 years ago, was an Epson - an excellent photo printer in its day. At that time the only precut 4x6 paper was not available at Costco and was very expensive as compared to cutting up the Kirkland paper. They were selling Epson Glossy Photo paper at that time. I'd buy a few boxes and cut all of one up into 4x6 pieces.
I would suggest that the cost of cutting three 4x6 sheets from an 8.5x11 as opposed to paying slightly less than 5 cents per precut sheet iis so close as to be negligable - similar to your analysis of the actual printing cost of two inks, the bulk cost of which is a difference of two times. The ink MIS sells, Image Speicalist, is also available from Precision Colors at a much better price, which brings the bulk cost of these inks closer to each other.
On my printers I print nearly all borderless photos. I haven't run into the dreaded waste ink full message yet. The little bit of overspray is conveniently collected in the foam area under the printhead path and doesn't harm the printer at all. Putting a stack of 4x6 sheets (Kirkland Costco paper precut) in the printer to do a big run of prints without the need to cut any paper is too convenient for me to do otherwise. I have, on rare occasion, had the trailing edge of a print with a bit of banding, and you do have to allow for a little bit of cropping which slightly reduces the image size, but the convenience is of more benefit to me than the chore of cutting any paper at all. My first inkjet printer, about 12 years ago, was an Epson - an excellent photo printer in its day. At that time the only precut 4x6 paper was not available at Costco and was very expensive as compared to cutting up the Kirkland paper. They were selling Epson Glossy Photo paper at that time. I'd buy a few boxes and cut all of one up into 4x6 pieces.