how often do you feed a cat wet food that is mid lvl to high lvl?

I sometimes wonder if i'm the only one that does this usually i buy high quality wet food but i sometimes get mid level quality food that doesn't have wheat soy corn in them. but when it's super super pricy i end up giving it to her as a special occasion day.

I usually Buy Evo, and I may end up doing Felidae

then in the middle of the month i give her 4health wetfood 2 of them twice a month

then I buy high super pricy quality ones like ziwipeak lamb and nature's variety rabbit (boy she really loves them)

I have a cat that loves wet food but my 2nd cat sometimes likes it but i ahve to take her to vet so she is not on wet food til i figure out what is wrong with her.

What kind of problem is she having? Is it diet related, in that you aren't giving her wet food?

If you're asking from a nutritional standpoint:

Sometimes high quality food is higher in calories than lower quality--many manufacturers list the calorie content on the can/bag.

If you're coming from a cost consideration:  I think you (all concerned caring cat owners) buy the best food they can afford.  Among the low end foods, some are better than others (Fancy Feast classic is decent).  Sometimes expensive foods come in larger cans (Evo), making the cost less on a per ounce basis.   Caloric dense, expensive foods can be good buys IF your cat is not food obsessed, i.e., self regulates.

 Some manufacturers tout "GRAIN FREE  NATURAL" which is good that the food is grain free, but doesn't necessarily mean it is low in carbohydrates.  Why pay $$$ for sweet potatoes?

I think mixing high/medium quality canned foods is fine.

I feed Ritz raw.  She loves loves loves rabbit and goat, but my pocket book doesn't.  So I feed her pork, beef, turkey and chicken on most days, and about once or twice a week, rabbit or goat.  (I buy meat on sale, sometimes further marked down when it is on its last "sell by" date; and I'm luckily in that my nephew is a hunter so get venison and goose free once or twice a year.)

Mixing up their diet between high and mid quality foods is just fine. Offering a good variety is always a good idea, in case of recalls, food going off market, or a "special diet" (your cat is more likely to eat it if used to variety) for health reasons, occurs you'll always have foods to fall back on. I have 3 to feed and sometimes have fosters also and cost is always a factor for me. I rotate Fancy Feast, Authority, and Great Choice Poulty plater in between their meals of Evo, Wellness, Natural Balance and a couple of others.