We don't see going from 2 -3 as being much more expensive. (but I can let you know for sure.. LOL)

However, that is the reason that stops us from going from 3-4 so I know where your DH is coming from. Cos my DH is exactly the same.

I just think with 3 you can recycle clothes and toys (especially if you have them close together ) so it doesn't really cost THAT much.

But, I'm of the opinion that you can get away with having a 3 bedroom house with 3 kids, and there a lots of people out there that wouldn't agree