Look harder for a younger home. Maybe go back farther in time than normal and apply a percentage for appreciation (after you accurately calculate that with median home values then and now). If none of that works, use older homes that have had major renovating to the point where they are effectively younger homes. Still in trouble, look outside the neighborhood for younger homes in areas of similar home values, school district, etc. This last method is less reliable because RE is always about location. Finally, take an older but similar home in the immediate neighborhood and calculate the rough cost of renovating it to the point where the home is functionally similar to your listing. Add that to its selling price. Also not terribly reliable but sometimes it's a useful supplementary approach. Do all of the above and everything should start to point towards a fairly reasonable value range.