Feeling lousy doesn't give much to go on? If the kitten is laying around, drooling, has discharge from nose or eyes, has diarrhea, won't eat or drink or play.........or is running a fever that all deserves a vet visit. They are still pretty young to be on solids all the way yet, you might try kitten glop (recipe is on www.kitten-rescue.com
Quality food is not about money per se, but more about ingredients and how you introduce the food which should be slowly and in small amounts. If you have flea-treated Kane with an over the counter flea treatment- get this kitten to the vet NOW! Over the counter flea treatments do not work, and they sometimes harm even kill. Fleas come in anyway they can find a route. They can jump 13 feet, so they can come in on your clothes, shoes, products you buy really anything. You should talk to your vet about how to safely de-flea small kittens, using adult strength products on them can make them very ill.
You can also always call your vet and ask him or her about Kane.