My experience of buying ink for computer printers.
Note that prices are estimates based on the Epson RX700 six-cartridge printer, which contain 17ml each.
1 I bought original brand inks.
Cost per cartridge - £10-£15. Total replacement approx. £72
Advantages: no need to consider any technical issues, ink should be good quality
Disadvantage: Very high running cost, esp if you do photos.
2 I bought compatible 'cheap brand' inks
Cost per cartridge - £4. Total replacement approx - £24. Jet Tec are good.
Advantages: large saving
Disadvantage: Original manufacturers claim there may be colour variation or fading after time with cheaper brands
3 I refilled my own cartridges
Cost per cartridge - typical web seller charges equivalent of £1.50 per cartridge (but see below)- total replacement approx. £9
Advantages: another large saving - can pick ink type
Disadvantages: need to buy syringes and learn how to do - can be messy.
4 I bought and used a Continuous Ink Supply
Cost per cartridge - typical seller charges £1.50 as above - I have found professional ink at £0.65p per cartridge. Total replacement approx. £3.90
Advantages: large saving - choose ink - refill with heavy use perhaps twice a year (though this must be done in scrupulously clean conditions!). I can now print photos with no concern about ink cost at all!
Disadvantages: need to fit system to printer - can be obtrusive. Depending on printer there may be need to modify it. Initial cost of CIS was about £45 (though it came with the ink equivalent of 6 cartridges for each colour, which would have cost about £140 if bought as cheap-brand cartridges.)
Recommendations:
Buy a CIS if one will fit your printer easily. It may be worth buying a printer to fit a CIS you know you can buy rather than the other way round.
Typical units are made in China and sold under a variety of names.
Two outlets are:
http://www.continuousink.com/ or
http://www.advancedinkjetsystems.com/Buy OCP ink in bulk from Promax. Web site is:
http://www.promaximaging.com/catalog/