Not all inks are compatible and unfortunately the Epson is the most expensive to repair. In the future I strongly suggest purchasing compatibles or ink from a reliable supplier.
Problem comes about when the customer uses several different brands of ink in the same printer.
The normal result is clogging of the printhead. Even the largest after market ink manufacturers can not afford to test their inks to work with every brand of the bath tub ink. Having worked for one of the OEM's and two of the largest after market suppliers, I can assure you that most Epson printers built today, should run about 40 cartridges before having severe clogging problems. That assumes normal use, not leaving the cartridge out of the printer for days and letting the ink path dry up. This is based on taking six printers, three running OEM ink only, and three printers running a quality after market ink after the initial OEM runs out.