I concur with those above who've said that it's important to find a decent supplier.
Like Jno, I use Inkredible. They're currently charging £8.62 for a full set of all FIVE cartridges for my Canon printer, or as low as £6.84 per set for buying in bulk. I usually wait until they've got a sale on though, meaning that I pay even lower prices and then buy in bulk as well. Their inks are every bit as good as 'originals' and there are no delivery charges. (They even operate a 'loyalty' scheme, giving yet more money off future orders).
I've also used Premier Ink in the past, and they're every bit as good:
http://www.premier-ink.co.uk
I've not used Choice Stationery but I've seen quite a few people recommend them here on AB:
https://www.choicestationery.com/
Just one last point though:
However good your inks are (even if you use 'originals') you won't get great results unless you use really good
paper. I've known people moan about the quality of their inks when the real problem is that they've been paying £2 per ream for cheap copy paper from a market stall and buying their photo paper from Poundland.
For top 'office quality' document printing I recommend HP 90gsm Bright White paper. Sainsbury's often stock it. I've seen it in The Works too, although they hadn't got any the last time I looked. John Lewis seem to be selling it at around half its full price at the moment though:
https://www.johnlewis.com/hp-a4-bright-white-paper-500-sheets/p2257484
For the very best photo printing (e.g. for a really important wedding photo that you want to frame as a gift), I'd recommend Kodak Ultra Premium photo paper:
https://www.pcworld.co.uk/gbuk/computing-accessories/office-supplies/paper/kodak-ultra-premium-a4-photo-paper-50-sheets-10132261-pdt.html
For other photo printing (e.g. when I design my own Christmas cards) I use HP Everyday photo paper:
https://www.clasohlson.com/uk/HP-Everyday-A4-Glossy-Photo-Paper/38-1037
Remember: To get decent results you need good quality inks AND good quality paper!