No one suggested it because he did not ask about dirt bikes. He indicated a preference for a beginner suitable sporty type bike and he wants to save money on gas. Hard to save money on gas if the bike is not street legal. It has been pointed out several times that a 600cc sport bike is not the best choice.

There is a lot to be said about learning in the dirt for safety's sake. And for fun, too!

A third option between street and dirt is a dual sport bike, such as the DRZ400. There are also many dirt bikes that can be converted to street legal use.

 

Motards are fun...and not bad to learn on either.

 

Above was the 'regular' dual sport version of the DRZ. There is a non-street legal DRZ400.

It does come in a super motard version, too.

 

If you've never been on any kind of motorcycle b4 I would suggest that you start with the Kawasaki 250. Motorcycles are not toys and are not to be played with. A 600 maybe too much for you, especially if you've never ridden b4. Stick with the 250, plus Kawasaki re-designed it for the 08 and it looks great.