Hi, thanks so much for your reply!

That's interesting to know - truthfully, I'm unsure of the printing quality I need for my greetings cards. I know the Canon Pixma iP8750 which I currently use is specified as a photo printer, although more of a hobbyist/amateur photographer rather than a professional printer like the Pro series I think? My greetings cards have quite bright and colourful designs but they haven't got masses of detail like a photo - I guess my art style is between realism and cartoony, probably leaning more toward cartoon really, so I wouldn't need a printer that gets every last detail, just that gives a decent print. Having clear text is important though as I use text on all of my greetings cards. That being said, I do really love the professional aspect of the Canon Pro printers - you mentioned the reliability and lifespan of them which is something I do worry about with my current printers, I just don't know if I'm overworking them with the amount of printing I do especially on cardstock!
As much as I do love the look of the Pro-200 (which is the only one I can currently buy online out of the pro series), the ink costs do worry me. At the moment I can buy 84ml of off-brand ink for my iP8750 for £17. In comparison, I'm unable to buy off-brand ink for a Pro 200, and the full set of official inks is £120 for 136ml.
Now I know off-brand ink isn't the best for printers, so if you can convince me that buying the official inks for the cost is worth it in terms of helping the printer last longer, printing quality and how the inks don't fade then I might be tempted! I have noticed that official inks (such as the ink that came with my iP8750, although I think they might have been... not full ink cartridges? like test ones which come with the printer?) they do last a lot longer than the off-brand ones I currently use. So do official inks generally last longer in terms of being able to print more compared to off-brand ones?
I'm not sure if the overall costs balance out in terms of how long a Pro-200 printer can last compared to an iP8750 with the amount I print. At the moment I can buy a iP8750 for £230, and probably replace it every 2 years. I'm not sure how long the ink cartridges I buy last, but they do seem to last quite a while still - I maybe change them every 2 weeks? This is from printing 10-20 cards a day 6 days a week. If a Pro-200 at £477 can last more than 4 years printing everyday, hopefully a lot longer if that's possible, then it'd stop me from having to buy a new iP8750 every 2 years - but then there's also the ink costs too as I mentioned above!
In terms of how long the print lasts before it fades - this is something I'm interested in. My greetings cards are all personalised which means a lot of them can be kept as special keepsakes - although most of them probably will be kept in a box, or on a windowsill for a week before they get chucked out. I do want to get more into creating A4 art prints though, specifically for children, which means the longevity would be important here if the print is sitting framed on a wall constantly in the light. It'd be nice if the prints would last for a few years without fading (they don't have to last 300 years + though like a lot of inks specify as I don't think they'd be around for that long!).