Believe me, I was ALWAYS on a budget! When we first began our homeschool adventure, my husband was a public school teacher—which meant his salary was very low. . . and I was at home with our kids.
But, where there's a will, there's a way.
We saved up for curriculum (often a great disappointment because it did not fit our family), we bartered our own products for other homeschool items at conventions, and we purchased things that turned out to be treasures. We ran the gamut from best to worst and back again!
So, my first bit of advice is to try to actually hold in your hands the books and curriculum you are considering. Despite the incredible advertising done on products these days, you may find that the can't-live-without book recommended on the internet is as unappetizing as yesterday's oatmeal. On the other hand, you may discover that it is a pearl without price, worth every cent! The only way to really know is to look it over in person, if at all possible.
Secondly, ask yourself whether it is good value. I have a very frugal homeschooling friend in Australia who decided to pay an enormous amount of money for a particular book, because it was exactly what she needed. And, do you know, a year later she still feels that it was worth the price! However, I have other friends who have purchased cheap curriculum that turned out to be extremely costly, because it was difficult to use, frustrating to their kids, and, essentially, a waste of their time. When making purchasing decisions, make sure you are comparing apples to apples, rather than edible apples to shiny cardboard!!
Next, check out your options. Does your library have the book, or can it be ordered through interlibrary loan? Does your church or support group or co-op or university have books or curriculum that you can check out? Are there online samples where you can try before you buy? (Here are my free samples online, in case you are interested in history.) Ask around and see if, perhaps, someone knows someone who just might have a copy!
Finally, and most importantly, I encourage you to pray. When my husband and I began to pray about how to survive homeschooling (back in the early days of my education failures), the Lord led us to a number of people and resources that absolutely transformed our lives. The One who has called you on your journey knows exactly what you need. And He is such a good Father, who genuinely answers His children's cries for help. What an adventure to take your needs in prayer to Him, and then watch and see His answers! That can be one of the sweetest parts of the homeschooling journey.
Remember, stay relational!