One thing to consider, which I don't think has been mentioned here, is that although the cost of some of the better varieties (and there are a number of good, wet, grain-free varieties out there) is admitedly often more expensive per can than most supermarket brands, typically one does not have to feed as MUCH per meal of the better quality foods. They contain less bulk/fillers and more quality protein, which is highly digestible (as opposed to fillers like corn which basically get pooped out with little nutrient uptake along the way). In other words, a cat that typically has to eat half a can of "poorer quality" food in order to maintain may only have to eat a quarter can of "better quality" food to maintain.
So, per-can...yes, most good foods are costlier. Per day, however, the cost usually works out to be less expensive. This is also very often the case with dry foods (not recommended for cats, but I experienced this myself with my dogs when switching to a better food, before we ultimiately switched to raw).
Solomon - black DSH - king of kitchen raids (11)
Gracie - Mutterooski X - scary smart (9)
Jaida - GSD - tripod trainwreck and gentle soul (4)
Heidi - mugsly Boston Terrier X - she is in BIG trouble!!! (3)
Audrey - torbie - sweet as pie (11 months)
Patrick - blue - a little turd (but we like him anyways) (6 months)
Boo, our Matriarch (August 1 1992 - March 29 2011)