BuddyPress.org

Does anyone know how much (server) memory is used by a single user visiting an integrated bbPress+BuddyPress installation (assuming standard installs and themes)? This could be a big impact on the ability of the system to scale to many users and lots of traffic.

I remember _ck_ (moderator on the bbPress forum) saying that it would be about 1MB, but that was before BackPress integrated a lot of the overlapping functionality.

How would one measure something like this?