Too often people/potential buyers go through houses built in the early 1900's or late 1800's and admire the old wood work, the built ins, the hardwood floors. But then groan when they see hundred year old wood windows. They automatically see high heat bills or a big window replacement cost.
Neither need to be true. I had a home inspector tell me that the best place to put your heat bill reducing dollars is in the attic. Secondly- you can restore those wood windows with a little money and a decent amount of elbow grease. And in the long run they will look a lot better than cheap (but efficient) vinyl replacement windows.
Below are a few videos with some instruction. You can always use the Google machine and YouTube to find additional instruction.