I contacted him directly at: http://www.athenstaxi.net/
Here is what we negotiated with him:
"The duration of Athens half day tour is about 6 hours.This tour includes;
The Acropolis, the changing of the guards, the stills of Olympia Zeus, our
national stadium, Saint George Lycabettus, the Greek and Roman
agora, and then lunch and shopping at the Plaka area.
The price for this tour is 130 Euros." (2 people).
I'm was assuming he will be our guide.
Thanks everyone for responding.