If you have cracked or broken seal glass in your window, any way you look at it, replacing the glass has big financial benefits.
Let's first look at someone who is thinking of listing their house. Window's are one of the key things prospective buyers look at. In particular, they look to see if there are cracks, or more importantly, foggy windows (on the inside) and mold. While replacing the whole window is expensive (and often not necessary), replacing just the window glass can typically be done at a very reasonable cost. More importantly, any work you do...you will recoup in the selling price (and you can point to it as a "feature" - all new glass). So that's one big financial benefit.
If you are not looking to list your house, you still realize the financial benefit of not having to replace the entire window, frame and all.
Either way, once you've replaced the window glass, you will reap the savings on your heating bill in the winter and your hydro bill in the summer. New glass will keep more heat in and cold air out in the winter and vice versa in the summer. You'll notice a savings and you'll notice you are more comfortable as you won't feel the heat/cold when you sit/stand by the window.
Also, if you use Low-e window's (which we recommend) you'll also allow your furniture/rugs/drapes etc., to last longer...saving you on earlier replacement costs!
Replacing your window glass if it is cracked or the seal is broken..makes economic sense!