Will window shrink-wrap make a noticeable difference in heating bill in house with single-paned windows?
You will almost certainly save $100 on your heating costs by using film, assuming you install it well and stop drafts through the window seals. It may also make the home feel more comfortable, which can be the primary benefit.
Also, properly installed film is virtually invisible. You hardly know it's there.
In my former home here in Minnesota we put the tape on the face of the casing, applied the film, shrunk it, then trimmed the edges close to the tape. My wife usually did the job and could do it in a few hours. It was a no-brainer for us even with storm windows over the single-pane double-hung units from the 1950s.