There are plenty of free resources on the internet that you can find to supplement your DD or DS's need for creativity and stimulation. You don't need whole books or anything else expensive. A library card is 1.00 and the books are free. Check out education.com for lots of activities you can do to teach your children all of the core subjects he or she would like at whatever level they are currently learning at all for free. 90% require just common household objects.

Never underestimate the power of Google.