会社の保険で(家族を含め)無料になってる人も多いですよ。BCでは上で掛かれたように無料のショットを受けられる範囲は決まってます。
https://www.healthlinkbc.ca/healthlinkbc-files/inactivated-influenza-vaccine
People at high risk of serious illness from influenza, such as:
Children 6 months to less than 5 years of age
Pregnant women at any stage of pregnancy during the influenza season
Seniors 65 years and older
Residents of any age living in residential care, assisted living or other group facilities
Aboriginal people
Children and teenagers required to take Aspirin® or ASA for long periods of time due to a medical condition
Children and adults with certain medical conditions, including:
Heart or lung disorders that require regular medical care, such as asthma, chronic obstructive pulmonary disease or cystic fibrosis
Kidney disease, chronic liver disease such as hepatitis, diabetes, cancer, anemia or weakened immune system
Those with health conditions causing difficulty breathing, swallowing or a risk of choking on food or fluids, such as people with severe brain damage, spinal cord injury, seizures or neuromuscular disorders
Those who are very obese
People able to transmit or spread influenza to those at high risk of serious illness from influenza including:
Household contacts of people at high risk
Household contacts, caregivers and daycare staff of children under 5 years of age
Doctors, nurses and others working in health care settings who have contact with patients
Visitors to health care facilities and other patient care locations
People who live or work in confined settings, such as correctional facilities
Those who provide care or service to people at high risk in potential outbreak settings such as cruise ships
Other groups who are also eligible to receive the flu shot for free include:
People who provide essential community services such as police officers, firefighters and ambulance attendants
Farmers and other people who work with live poultry
もしかすると、ドラッグストア側としては「ハイリスク扱い」で打たせて、州に請求してるだけかもしれませんが(店側としてはお金が入って来れば問題無い訳で)