Hi Davesbubby
Im TTC#1 and i think yours is a very good question. Although im not an expert, these are just my thoughts
There needs to be $ consideration for medications/herbal things you take while pregnant, doctors visits.
The cost of the birth and the stay with hospitals + excess

I think clothing and furniture wise. its like any adult person you can be buying from a discount store or an upmarket boutique or going secondhand. Safety should be considered foremost. Ive started looking at baby clothes, and there are these little things with huge price tags!

Nappies- cloth vs disposables - can you put a price on convience?
Forumula vs Breastfeeding-

Lost of baby sites, give an "essential lists" they could be useful to see all the things you can have. I dont know if i can mention them or not, so i wont for now.