This book mentions the minimal initial co-parenting costs (providing the mother has health insurance.) Raising the child obviously has costs, and this arrangement should be spelled out with a co-parenting contract before the baby is born. There are different levels of involvement-- from a 'close uncle' role to a 50% level in child-raising duties. It also mentions a scary prospect--a biological father saddled with child support without custody rights. Of course, these issues are defined by state law.
