There's a third route to take:
Larger carts of the OEM ink can be less than 1/3 the price per ML compared to smaller carts of the same OEM ink. For example 0.23 Eurocent excl. VAT per ML on a 775 ML cart compared to 0,78 Eurocent per ML excl. VAT on an 28 ML cart. Bigger investment for some users but with all the advantages of using the right ink on the printer. Refilling carts from larger carts isn't difficult.
While I have used third party inks (early pigment) when the big printer companies had no suitable inks on the wide formats I wouldn't recommend it anymore. There were color shifts in the inks per batch that made consistency of job repeats difficult. The third party pigment inks had more pigment settling if not used frequently which also contributed to less color consistency and damper clogging. Dye inks are another category but I can not use dye inks for the jobs I have. There have been improvements in third party pigment inks since I used them but the color inks are not matching the fade resistance of Vivera pigment ink for example. The last ink can even be used in Epsons which Paul Roark showed with the PK Vivera in an Epson 1400 (1.5 picoliter droplets). No clogs reported, neutral black, excellent fade resistance.
met vriendelijke groeten, Ernst Dinkla
New: Dinkla Canvas Wrap Actions for Photoshop
http://www.pigment-print.com/dinklacanvaswraps/index.html