A growing number of parents are choosing to have their children's cord blood stored in private banks at a cost of anywhere from $3300 if you pay a lump sum to $5460 if you spread it over 18 years. The hope is that the stem cells contained in the cord blood could provide invaluable treatment one day. But some experts worry that marketing by private cord blood banks may pressure vulnerable parents, fearing "what if's", to gamble their baby bonus or savings on treatments that aren't yet based on sound evidence.