I've read a lot of negative reviews and low ratings on Canon inks, so I wanted to point out a couple of things to think about to those that read the reviews and using them before buying. You may find this same review on the different ink colours from Canon, but I don't work for Canon and I'm not a fanboy of theirs either (I prefer the digital cameras from their main rival actually!) - I simply use Canon printers and inks.
1) Some reviews are not rating the product, they are rating the delivery cost of the item. Whilst this is an important part of the purchase, I don't think it is justified to include this in the rating because Amazon provide free delivery if you spend £15 or over. This can easily be done by buying two cartridges. Myself, I tend to buy four or five at a time in order to have plenty of spares before large print jobs.
2) I believe some of the negative comments about delivery arise because the products are being bought from a Marketplace Seller and not Amazon themselves. Yes, clicking on 'Add to Shopping Basket' does automatically order from the vendor listed after 'Availability' (look carefully next time), but if you look to the right of the page, under 'More Buying Choices' and click on 'x used and new', you can order from Amazon themselves. Granted, it is more expensive but the free delivery makes it cheaper overall.
3) If you are not really concerned about the quality of the printed output, then yes, you can certainly buy a cheaper alternative from a third party. However, don't expect the printed results to be as good as those using Canon's inks and papers because all printer manufacturer's papers and inks have been developed to work best WITH EACH OTHER. The chemical properties of paper and the ink vary between manufacturers so different combinations produce different results, eg. Epson papers produce a magenta tint on Canon printers, etc. Don't take my word for it though, this topic has been well researched by Photographic and Computing magazine reviews, as well as average users who have experimented expensively (like me). If you really want or need the best quality prints, perhaps because they are being sold, then you cannot get better results than using the manufacturer's original ink.
4) Be aware that certain third party inks MAY (not WILL) damage your print heads, which can be costly to repair. There are several online forums testifying to this.
5) Compared to the price of other large brand inks, Canon's ink prices are about the same. Have a look on this very website at HP's inks if you want to check. Bear that in mind when reading reviews complaining at the price of the product. (I seem to remember that at one time HP ink was officially the 5th most expensive liquid in the world, even more expensive than top notch Champagne!)
I hope this is useful or helpful to readers, but feel free to disregard anything I have said as merely the opinion of another mortal!