Hi Kg, Ink usage varies based on a number of factors, like ink coverage per page, driver settings, temperature and humidity. Ink yield for the ET-2720 averages 4,500 pages from a 522 black ink bottle and 7,500 pages from each 522 color ink bottle. The first time you load ink a small amount is used to prime the printer. The remainder is available for printing. You can base your expected cost on this information and the cost of the paper you expect to print. Regards, Mark - The Epson Team.