I use a Canon printer (Pixma IP3000), with 3rd party inks. On the High Street, I pay about �3 per cartridge (for the Print Aid brand). Online, I pay about �2 for black cartridges and �2.50 for colour. InkCycle offer excellent quality products, together with superb service:
http://www.inkcycle.co.uk
As with Epson, there are cheap inks available for most Canon printers but some models still use very expensive cartridges. The only sensible advice is that you should research the cost of ink, for specific models, before committing yourself to purchasing from any particular manufacturer.
Chris