I will answer both of your guestions first high carbon or Magnalite type frame likely means 25lbs give or take couple not under 23lbs. You will find very few vintage road bikes that weigh under 23lbs but I have never had a issue with a legit 25lb bike if everything else is good. Stop worrying about wieght you need to focus on guality and components. Second yes $300 is too high for this bike considering condition issues and the fact this is just a mid level Japanese bike with a Bianchi label don't be suckered buy the bike based on the bike not the brand. Based on the bike it is only worth about half the asking price.