Keep in mind, that any valid study you find (that is based on actual photos, using high quality photo paper), is likely to be based on Factory Papers and Inks.
You can usually do much better by shopping online (or watching for sales) for your supplies. So, take this into consideration, too.
Also, as Slipe mentioned above, you can save a lot of money by going with third party ink and paper.
I use3rd party paper, but I don't use 3rd party ink (I'm using an older HP Printer PHotosmart 1215 as my primary photo printer). With my HP, you replace the printheads, everytime you replace the ink cartridges. So, cost does seem to be a bit higher than with other manufacturer's printers.
However, I don't have to put up with clogged nozzles, or need to run cleaning cycles (which waste ink) with my HP. So, the cost difference may not be as great as sometimes perceived. I've never yet had a clogged nozzle on my HP. I can't say the same for other photoprinters I've used (although I'd hopethat inkjet printers are gettingbetter with this now).