I wouldnt listen to trbodrmr

Brand new 600's run for mid to low 8's. If you ever paid 7k or anywhere near it for a 98 you would be getting robbed. 03' gixxers w/semi high miles go for low-mid 7's.

I suggest going with a 600 personally, they are very good to start on, I love my 636 and it is still plenty of power without having to worry about lifting the tire everytime you want to romp on it. Most people agree that more then a 600 to start is too much...so I was just letting you know.