Chicken pox is not a concern for children. No one had a vaccine for it when I was a kid and everyone caught it and it was sort of normal. Chicken pox is mostly a concern for adults where the symptoms are much worse.
When people mention vaccines and how they help children, it's about the SERIOUS diseases! Ie, measles can be fatal. Bringing up the minor stuff just puts you into the anti-vaxx hysteria camp.
Just because you don't know any kids who died of chicken pox doesn't mean it is super rare.
"Chickenpox used to be very common in the United States. In the early 1990s, an average of 4 million people got varicella, 10,500 to 13,000 were hospitalized (range, 8,000 to 18,000), and 100 to 150 died each year. In the 1990s, the highest rate of varicella was reported in preschool-aged children.
Chickenpox vaccine became available in the United States in 1995. In 2014, 91% of children 19 to 35 months old in the United States had received one dose of varicella vaccine, varying from 83% to 95% by state. Among adolescents 13 to 17 years of age without a prior history of disease, 95% had received 1 dose of varicella vaccine, and 81% had received 2 doses of the vaccine. Eighty-five percent of adolescents had either a history of varicella disease or received 2 doses of varicella vaccine.
Each year, more than 3.5 million cases of varicella, 9,000 hospitalizations, and 100 deaths are prevented by varicella vaccination in the United States."
I don't know how much the hospitalizations and deaths should be priced at in comparison the the "costs" of varicella vaccination, but similar arguments to your could be made for seatbelts - nobody I know died because of lack of seatbelts before they were mandated.