I think you need to see if your corner lot is extended with higher build up or not and also the condition of the house as well as the renovation the owner put in. Many factor to determine the price of that corner lot.. But if you are saying the build up is the same, just the different is the extra land, I would only give around 550K max. Anyway, different people different opinion, You have to justify how much you willing to pay, but all also come down how much owner willing to let go...