Video game question - Fight Night 2 or 3?

[posnera]

As opposed to the things I like to pay too much for, I am a cheapskate when it comes to video games. I am ready for a new one, and boxing it will be.

Is there enough of an improvement to make the new version of Fight Night worth it? I haven't played either one. It doesn't sound like the gameplay has been changed much, are the graphics much better?
Round 2 is going as low as $12.99 (used) vs. $39.99 for Round 3.

Equipment: PS2, big ass plasma TV