I would offer $900, but pay up to $1100 if it truly runs GOOD! If its not running really good, or you can find any mechanical problems that you can point out to the seller, offer him $700 and only go up to $900. Look for signs of oil leaks, loss of pull through the throttle range in low gears, and sounds in the motor like ticks and clicks! If you find one or more of these, start reducing the price! Act like you know everything about these bikes and you have worked on these things for the last 5 years! If you can pull of that you know more about the bike than the seller, you will have more bargaining power. I don't think this bike is really worth $1300 but could be if it is in really really good shape! Like no rust and perfect new condition minus some small signs of wear and tear! Only go $1300 as a last resort if you just fall in love with it! Good luck and let us know how it goes!