To my knowledge, this is the only book signed by any stars of the show. I have seen a couple signed by comics creators that worked on the books (Neal Adams and Joe Staton, again as I recall) but never any signed by the cast. Even so, this is the highest and only graded copy of this book.
When it comes to TV shows that influence or have had an effect on people's lives, Star Trek is generally the first show that comes to mind. That's a really good one as it has influenced scientists in all fields and has driven a great many other changes and that is both fantastic and amazing. I would argue though that another, much less famous or enduring show has had a much bigger effect on virtually every American. Have you ever heard of EMERGENCY! ? It premiered in 1972 and, depending upon your source, there were either less than 10 or only 12 paramedic units in all of the U.S. Paramedic "units" doesn't necessarily mean ambulances either. As seen on the show, some paramedics rode on rescue or other fire apparatus. As of 1977, more than half of all American were within 10 minutes of a paramedic staffed vehicle, be it a fire engine, rescue, ground ambulance or air ambulance. Paramedics and EMS in general have driven changes in medicine and increased survival rates for a wide variety of injuries and maladies from asthma to strokes. While a great many of these changes were likely inevitable, EMERGENCY! brought the idea to the forefront, making the public aware of what was possible and in turn pushing leaders to expand EMS nationwide.
So while Star Trek may have more of a wow factor and may have influenced more lofty minds and goals, EMERGENCY! has probably had a much wider effect. I know it influenced me in my youth, planting the seed of fire fighting and EMS that would eventually turn into a career. I've been watching for the stars of the show to turn up for signing for a very long time. I've got half of the team of Johnny and Roy (their characters' names - I'm not sure why they used the actors' names on the cover) and will be looking out for an opportunity to add Kevin Tighe!