The Epson 'Chip' calculates 'Ink Use' by counting the pages passed and then saying 'Oh yes xxx pages -you've used all your ink- when if cat you may have been printing off letter heads or similar with virtual no ink use at all.
Invest in a Zapit- chip re-setter
and refill kits to suit.
Also check out
that will save even more money.
But then perhaps you know all this already