Developer proxy for weighing pages

As a web developer I am keen on weighing my pages.

Yes I know kb is not a fool proof measurement when there is caching, proxies, DOM rendering and all to make measurements more complex.

Instead of weighing my pages now and then – why not weigh them all the time? Say I have a proxy like Fiddler and there count the kilobytes, number of calls and whatnot to dump into a database. A program then does some calculations and returns a graph and some figures about what it has found. It can either send me an email at noon and an hour before I leave or it can show data continuously like Growl or Miniprofiler.
I believe there has to be some data filtering to erase pages not fully loaded (I develop you know) and loading times of the scale (I develop you know).