Over the last few years, OEM ink prices have significantly dropped making them more reasonably priced than ever before. But if you start comparing them to after-market inks and/or continuous inking systems, they are still a lot more expensive and you could be tempted to think of using these instead. We would strongly advice you against this as, quite simply, in the long run its just not worth the hassle. We can't tell you the number of people who have, over the years, come a major cropper due to issues with after-market inks - either broken printers, unexpected colour shifts, unresolvable clogging issues etc.
original inks from Epson, Canon, and HP are really pretty special and
have been extremely thoroughly researched and tested. No matter what
the after-market ink suppliers tell you, their ink testing doesn't come
close to the OEM inks. We've been contracted on several occasions to
test inks for these companies and the lack of consistency and quality is
evident when they're compared to the original inks.
The original inks are fantastically similar batch to batch, year after year. Indeed, even with sophisticated equipment, it is almost impossible to measure any batch variance in, for instance, Epson Ultrachrome ink. They are simply always the same, time and time again.The most expensive after-market inks still have huge measurable variance within a single year. The quality control is simply not there - the density of the inks is often a very good match for previous batches but the hue (i.e.. the actual colours) are quite measurably variable batch to batch. This is most likely why they don't publish the results of our ink testing for them!
Further, the design of the original print-heads is intimately correlated to the ink formulations for that generation of printer. Very slight tweaks in the ink formulation usually require a new design to the print-head for ongoing reliable results - you have to remember the print-head in a modern inkjet is a fabulously intricate and carefully produced device. If you start running inks through your printhead with even a slight variance to the intended inks, such as a slightly more viscous ink, or one with slightly bigger particles, you will begin to damage your print-head and degrade the performance of your printer over time.
Whilst they tell you their inks are 'just as archival', the OEMs have had significant independent testing done to back up their claims and their ink really IS archival. We've had numerous phone calls from artists who have used CIS inks over the years then found that whole batches of prints they have sold have had very significant colour shift over the medium terms (i.e. just a few years).
Fixing this issue can come at great cost - in re-prints, and to your reputation as an artist. With 15 years of experience specifically in this area, we can say with certainty that almost all CIS users have significant hassles over time one way or another. Sometimes you might get a year or two of reliable use, and save significantly on the way, but the problems always arise eventually.
We have had simply so many phone calls over the years about colour change issues, lack of profiles, ink leakages, clogging issues, destroyed print heads, etc. It simply is not worth it and if archival, high quality fine art prints is your goal, you simply must use the OEM inks.