Agreeing with the other reply... You can homeschool for very little if you utilize the internet and the library.
You can find and print/copy tables' of contents to use as 'spines' to make sure you cover the major topics. Then you can find free, printable worksheets and videos on the internet to flesh it out. They are ALL OVER the place - just 'google' the subject along with 'free' or 'printable'. Check out the History Channel on-line. You can find lots of great educational stuff on YouTube, too, just make sure to preview it.
If you can spare the $$, I'd use that on good math and science curricula - even if you have to buy used textbooks somewhere (like from amazon, ebay or garage sales). You might even look into a co-op. Sometimes if you teach, you can get your kids in at a discount.
I''ll give you some links to get you started. Good luck - hang in there.