What would be a fair estimate, of how many people were born on earth and died so far (not counting the living ones, of course), since the first man?

I'll go with about 100 billion.

As of 1995 one educated guess put the figure at 109,947,781,641, or about 110 billion.

Source:
http://members.bellatlantic.net/~bjmcg/story2_peple_lived.html