There are some great books out there for those who are considering a homebirth, and aren't sure, or who want to convince a reluctant DH or other family members. One that's coming to mind is "Special Delivery" by Rahima Baldwin, and also "Homebirth" by Sheila Kitzinger. I'm sure if you talk to your local midwives' association, they could give you more resources to go on.
As far as costs go, I guess you could say it's an investment in the health of yourself and your child, but I don't know what my decision would be if I had to pay! Here in Canada, it's totally covered.

Anyone else thinking of a waterbirth? I just read Kelly's article on it, and am more curious than ever to try it. I'm not making any firm plans though, 'cause I don't know what I'll want at that moment, but my midwife is open to the possibility, so we'll just go with the flow.