Query about updates to 10.5

I am in need of a laptop, but want to wait until Leopard comes out until I purchase one.

Considering that the first couple versions may be buggy, I was wondering what the policy was in regards to updating 10.5.xx when it comes out. If I buy the initial version, do I have to pay to upgrade to 10.5.xx when it comes out after a couple months and less buggy?

Thanks for the help. BTW, this is my first post. I'm on my way to my first Apple purchase (aside from an iPod).

 

Thanks, that's what I wanted to hear.