2008 Kawasaki NInja 250 is what you need if you are a new rider.
$3500 new!

I do however know that I don't really want to begin on anything less than a 600.
Mmmm, no... you don't know squat. Put me on a 250cc and you on a 600cc and I will whoop your ass around a track all day.

There is no reason a new rider needs the full power of a 600. The only 600cc I would recommend as a starter is a Katana