Actually, I shared this in other topics..
in the presence technology, private banking is not "cost-effective", you nearly have no chance to use the stored stem cells. Therefore, donation is a good choose.
however, many scientists are working on the research to manipulate/cultivate the stem cells into specific cell types, e.g. nerve cells, cardiac cell.. etc.
so, if you believe that, after say.. 10 or 20 years.. the research may go into clinical use, then, the stored stem cells will be a treasure for your child.
please take noted that.. the world trend is storing stem cells in "bag" instead of "vials" in the old days (for many results.. one is more ez to handle when transplantation is needed.) so, how many "units" are the preserved stem cells stored.. might be one of your consideration.