Can you give some info on you're usage and the amount of ink it uses in maintenance cycles per month (or year)?
My current 8300 maintenance tank is at 40% and has been in place over a year. That's incredibly good compared to my previous 9880 and 7800. I leave my printer on all the time and if there is any incremental loss of ink to maintenance cycles it doesn't amount to much at all. But I print almost every day, so maybe that affects ink use in a good way.
Since the latest 1.26 firmware update the printer seems to do either fewer or no scheduled head cleanings of its own volition, except very rarely for brief "head cleanings" mostly at the conclusion very big prints. But it does wake up about once a day and agitate the inks. I have heard that the new firmware characterizes how the printer is being used and adjusts its automatic maintenance chores accordingly.
The bottom line for wide format printers is that they are production machines and will be far less economical if used sparingly. The economic decision to buy one has to be seen in the pragmatic light of profit per print after costs, or how important the ability to closely control print quality is to the owner, or how advantageous it is to quickly supply clients with prints, etc. That puts the artist and hobbyist with small output in a tough spot because of highly deferred or no income at all from printed work to balance recurring costs. There's no question that low duty cycles will result will in greater costs. You either need to making money from the machine, or you need to want to make prints so bad it hurts.
PS there will probably be another Canon promotion around Easter.