In their latest (March 2009) issue, Consumer Reports has a very readable article , including quotes from a Cornell University vet, about whether it’s worth spending lots of money on fancy cat food (for those who don’t like clicking on links, here’s the answer: no). Unless your cat(s) have specific health or age issues, any decent generic food should do if their little cat tummies tolerate it.
And since wet food is 75% water, it costs a lot more per ounce of real nutrition, so the same rationale goes here: unless they need wet food for a specific reason, dry will do fine. What with the recession and all, it makes sense to save money on regular purchases (like food) to serve as a cushion in case of unexpected medical bills, or whatever.
Of course, none of this means you shouldn’t buy cans of salmon or fancy treats for your dear cats. Just use them as treats, not everyday meals!