Make no mistake, homeschooling is a full time job and time-savers in the kitchen are a real blessing. But rather than over-spend on some packaged convenience food, you can buy the less expensive raw ingredients and make your own.
There are several sources of recipes for making your own mixes. While I normally advocate finding everything possible for free, I will say that this book: MAKE A MIX has many recipes I use on a regular basis. Perhaps you can find a copy at your local library. It's apparently just been reprinted, so if you're fortunate enough to live in an area with a good library system, even if they don't currently have a copy, you might be able to request they obtain one.
In any case, if you happen to stumble across it at a garage sale or used store, consider picking it up.
** Note - one thing I've found with this book is that the recipes for the sweet quick breads all seem to need about 1/2 cup water added. Doing this has produced much better results for me.
Meanwhile, here are some free resources for make-a-mix recipes.
BUDGET 101 CONVENIENCE MIXES
When I first started using mixes, I only kept a biscuit mix, a white sauce mix, and a "Shake and Bake" type mix on hand. Now I have everything from cookie mixes to flavored rice. I found some "vintage" Tupperware containers (read - several in dark orange and the rest in mustard yellow - gotta love those 70s colors!) on auction and paid $7 for the lot. Now they crowd my pantry shelves and freezer. I have found the genuine item here - Tupperware - does seem to keep my ingredients fresher, longer, but you might be able to find another brand/maker that works equally well.
For an example of how I use my mixes, on Sunday afternoons, I get out my biscuit mix, sweet bread mix, and whole wheat mix, and get to work. I make a batch of waffles and some pancakes. These I freeze. I will make 2 dozen muffins of some sort - depending on what I find on sale at the store, like zucchini, apples, bananas, or carrots. Finally, I'll make some dinner rolls. I do not make sandwich bread - I buy that at the local thrift store, once a month on the "everything is .65 cents" day. This may sound like a lot of work, and certainly it takes time, but now that my routine is established and my kids are able to help - they actually *like* cooking pancakes - we get it done within a few hours and I have all the baked goods we need for the week.
Except cookies, that is. There's just something about fresh-baked cookies! Whenever we want a treat, I get out my freezer cookie dough and make a dozen. They're so great right out of the oven (with just a bit of cooling time) with a glass of milk. And they make the house smell yummy. :)
During the week, my kids can choose muffins, waffles, or pancakes for breakfast. They take them directly from the freezer and either microwave toast them. They eat these with some kind of fruit - either fresh, or something prepared like our homemade applesauce - milk, and sometimes we'll scramble some eggs. In colder weather, which, here in Central Florida is only about 2 months out of the year, we'll also make oatmeal on some mornings.
Our breakfasts, even with fruit and milk, typically cost only around .40 cents per serving. Keep in mind, one serving of milk is only eight ounces. If you have kids who tend to pour enough liquid to fill the glass, no matter how big the glass actually is, make sure they're only using smaller "juice" glasses, or take over the drink serving yourself.
Another advantage? Our breakfasts are no more difficult to prepare each morning than a bowl of sugar-coated, expensive cereal. We have breakfast on the table in 5 minutes or less, and clean-up is a snap, so we can dive right in to school work, leave for our weekly shopping on Saturday mornings, or church on Sundays.
If you've never been a mix person, and you're wondering where to start, I recommend the same place I did. The biscuit mix is very versatile and can be used for more than just breads/rolls. (Check out the Bisquick website for other ideas.) Having a white sauce means you'll have a quick base for a cheese sauce you can serve over veggies or pasta, Alfredo sauce, and it can be used, mixed with some milk, in place of canned Cream of Whatever when it's called for in a recipe. A "fake" Shake-n-Bake recipe is nice to keep on hand to quickly season chicken, pork or fish pieces for an easy entree. Once you start using one kind of mix, you'll quickly start exploring the many others out there.
One final note - some mixes call for bouillon granules. I recommend you purchase the no-sodium version, even if it costs a little more, if you can find it. Regular bouillon granules have an incredibly high salt content - something like 35% of the RDA for a teaspoon amount! Eek!