Cord Blood Banking?

I'm starting to research Cord Blood Banking. I've registered to receive tons of info about the benefits of it. It seems like a no brainer -- of course I want to have the option if my child ever gets ill! But the cost seems kind of steep ($2,000 - $3,000) with all the other expenses adding up. My husband thinks we should absolutely do it, that we will find the money. I am leaning towards that as well, but I wonder how many people have actually had to use the cord blood they banked? What circumstances is it good for? How long does it last? So many questions... I just want to make the best decision.