Materials were not cheap. I think I paid $105 for lye, coconut oil, palm oil, peppermint essential oil, vanilla fragrance, shea butter, grapefruit seed extract, and beeswax enough to make a little over two batches of soap and shipping for all of those. Then we also purchased distilled water and olive oil separately for $25; there was enough water for four batches and olive oil for three.
So if I engage in a little fuzzy math and round out the number of batches to 2.5, the cost comes to $52/batch of soap or $1.11 per bar. Probably not super-frugal; however, we didn't add the value of the chemistry lesson for the girls, and when you consider the cost of buying handmade soap as a gift, it becomes incredibly cost-sensitive.
Thanks to Miss Hannah for the instructions and help getting supplies!
Also, it looks like another mutual friend found a local option for buying supplies which would cut out the exorbitant shipping costs. The first list of supplies was $27 to ship, which added $10 to the cost of each batch or about $0.21 to the cost of each bar. Apparently, the local option also is less expensive for the supplies, as well. Win on all fronts!