>>>it suggested I may need a new printhead and it shows how to fit one
I hope not! I've never found ANY printer where the cost of a new print head isn't substantially MORE than the cost of a new printer!
If you need a new printer, look for a Canon model that uses separate ink cartridges for each colour; it will save you a fortune in the long run!. Then buy decent compatible inks.
This would be my current recommendation:
http://www.pcworld.co.uk/gbuk/printers-ink/printers-scanners/all-in-one-printers/canon-pixma-mg6450-all-in-one-wireless-inkjet-printer-21737241-pdt.html#cat-0
with inks from here:
http://www.inkredible.co.uk/inkredible-saver-canon-pixma-mg6450-ink-cartridges
(£30 will buy you FOUR full sets of 5 cartridges, so that's just £1.50 per cartridge)
NB: Those recomndations aren't just based upon a bit of googling. That printer is an updated version of the Canon printer I use myself and that ink supplier is where I buy my own inks from. I get superb quality prints!