Overall, I believe the most expensive part when raising a baby is diapering. However, this financial burden is easily overcome with a handy sewing machine, knitting needles and crochet hook. I created an entire stash of diapers (about 30 or so) out of a flannel sheet set from a used goods store for under 10$. Wool soakers were created with wool sweaters from the used clothing stores as well and they work quite well as long as baby is changed frequently. I've also created fitted diapers out of flannel fabric. To create wipes, I bought a set of white terry cloth wash clothes from wal-mart, cut them in quarters, and then sewed around the edges to keep them from fraying in the wash. A solution of olive oil, tea tree oil, vitamin E and warm water is added to a spray bottle for moisture on the wipes. I prefer to keep the moisture out of the wipes until ready to use because mildew often accumulates on the wipes. Cloth diapering can be fun especially if you have a little extra cash on hand and you like to create some fun looking diapers for your baby.
For more information on frugal diapering check out:
http://fernandfaerie.com/frugaldiapering.html
http://www.borntolove.com/frugal-index.html
http://www.diaperjungle.com/sewing-cloth-diapers.html