Quality of paper.
Wholesale or volume versus retail purchase of paper.
Inkjet cartridge supplier.
Discount or full retail price on ink cartridge.
Printing plain text, text w/images, or photographic-quality images.
Reverse printing (white on black on white paper) versus normal (black
on white paper)
Draft versus normal versus high-quality print modes.
Letting cartridges dry out so their ports get plugged with dry ink
that results in trashing a cartridge with ink still in it (i.e., not
using the cartridge enough to keep the jets clean).
Whether you are purchasing cartridges for late model, antiquated
models, rare models, or popular models of printers.
Which brand of printer, availability of cartridges, production volume,
number 3rd party cartridge suppliers, market competition.

I'm sure there are lots of other factors to the cost per page.  Since
only you know which brand and model of inkjet printer that you have or
are considering to purchase, what paper you will use, what you will
print, and if you will buy the brand-name retail cartridges, 3rd party
cartridge suppliers, or refill the cartridges is only known to you
since none of that was divulged in your post.

You obviously have Internet access.  Do your own research on whatever
you use or intend to use.

I don't think that it is that expensive but like VanguardLH said there
are many factors to consider to get an accurate cost per page.  Everyday
use paper costs about $5.00/ream, a ream is 500 pages so paper for
everyday printing is as little as one cent per page.  The ink cost and
approximate yield information you can find on the net.  To that you have
to include the printer cost, for good quality printers the MTBF (Mean
Time Between Failure) is often given and expressed in number of pages
printed, so a printer with a MTBF of 50,000 should yield about that many
pages, that is its about useful life, divide the cost of the printer by
the MTBF and it will give you an approximate hardware cost per page.

My findings with this is that the old saying "You can pay me now, or you
can pay me later" certainly applies to printers!  Ink for cheap printers
is way more expensive than for the more expensive ones and manufacturers
usually don't publish MTBF information for the cheap printers, I can
tell you that they don't last too long and the hardware cost is usually
much more than for expensive printers.  Another cost often overlooked is
the speed at which the printer prints and the overall quality of the
prints.  If you are paying an employee to print 100 pages on a printer
that prints 4 or 5 pages per minutes and that blotch half of them the
cost per page is going to be in the dollar range, not pennies!

In the end it is up to you to decide what you need.  Try to estimate how
many pages you print per month and try to get a printer rated for a bit
more than your monthly average.  I think that nobody regrets spending a
bit more for a good printer, they are worth it if you do any amount of
printing.  I think that you should leave those $79 clacketty printers on
the shelf, they're not very reliable and the replacement ink usually
cost more than the printer!  Not to mention that after you run 2 sets of
cartridges and about 1,000 pages through the printer it will probably
break down!  In other words, you get what you pay for.

John