Tough choice, the F doesn't look like a $999 bike to me either. If there's no title for the K, $600 is kind of high, any clue how hard it would be to chase the title? is the seller the last registered owner who lost the papers or did he get it from a friend of a friend? Personally, If you have the time and the money, I'd offer 4 or 5 for the K and start rebuilding the motor while watching CL for another one with a title, or a titled frame. Once you get one in the garage, they start attracting each other, you'll have a garage full soon. Welcome to the club!