You do not need the most expensive flashy books you can find. There are books on every subject you need at the library. Ask around, somebody is bound to have something you are looking for. We have been on both ends of giving and receiving, help and be helped. There is always someone that is happy to get rid of books that have been piling up that they no longer need.
Join homeschool chats and homeschool Facebook groups, many deals are advertised where you can buy second hand books or trade in. So many groups have popped up now, not just for South Africa and its provinces but for areas too. Find homeschoolers in your area and get connected, all it takes is a search on the internet.
Speaking of the internet, there are unlimited free resources for all subjects, any age or grade. They range from writing sheet print outs, to YouTube videos of volcanoes erupting, science experiments, the list is endless, you search it – it is there. This can be one of you greatest tools.