Black ink tank refill
The first time I purchased my ink-tanks for my Epson Artisan was in 2010, I then discovered MIR-AUS online where I could buy the refills, which I purchased all the colours in 2014. The ink-tanks lasted four years - and that's with a lot of both colour and black printing of full A4 pages.
In 2016 I purchased just a 100ml black ink refill bottle.
And this year I have purchased another 100ml black ink bottle.
So depending on how often you use your printer and whether or not you use black ink a lot or colour, the black ink refills can last from between 2 to 4 years; and the colour inks from 4 to 6 years.
Extremely thankful that MIR-AUS is still operational all these years later as they are my one and only go-to for the ink bottle refills. Plus the customer service and delivery is 10/10!