It is your money, your checkbook, your decision. "Fair" to me means....that which is equally agreed upon by all parties of a transaction. "Location, Higest and Best Use, Economic Contribution," and so may other factors are needed to "fairly" answer the question. Real Estate is a business of negociating. Remember when working with a REALTOR, you are with a partner who, has taken as oath to have your "best interests" as the primary factor in that negociation towards, "fair."
Hope this helps.