Where?? I keep hearing about these but I never see them at the grocery store. It seems like a jackpot item for grocery stores to be able to charge a margin.
In my Walmart the meal kits are usually near the refrigerated meats or in the produce section. They have things like pot roast, meatloaf, spaghetti, salad kits, soup kits, etc. I've seen a few extra soup kits near the canned soup and/or near spices. At my Publix they have some area where they give out free samples of a meal idea now and then, and there is a fridge next to the booth that has the ingredients to make the sample meal and a recipe card. There isn't even an upcharge for that. And I live in a smaller town.
Personally I just look on allrecipes for something that looks good and follow the directions.