Is this a fair price?

http://newlondon.craigslist.org/mcy/3857867667.html

What's this worth?

It's probably about right as priced.

http://www.cycletrader.com/Honda-Cbr600-Motorcycles----Cycletrader.Com/search-results?type=356953&make=Honda|2316874&model=Cbr600|764948688&trim=600|3904&year=2000:2002&modelkeyword=1&sort=featured:desc

It may need a chain at that mileage if it hasn't been done already, D&D exhausts are about the loudest sold, and if it wasn't well tuned that Power Commander may be more trouble than it is worth. I wouldn't pay less for a bike with one installed as long as it's a clean installation and there's proof of time on a dyno, etc from the install.

I say go for it and offer $3k to see what happens. That said, I'm a VFR fan, so take that offer number with a grain of salt since I don't have a lot of experience looking at other bike seriously.

three years ago, my wife sold her mint 15k mile red/black 2001 F4i for $4500.

These bikes a famous for having the cam chain tensioners go. Listen for a rattle when getting off the gas and if it is there, use it to knock the price down and get a manual tensioner for $100.