A) it’s free. At almost any clinic, most large employers clinics on site, grocery stores, targets, etc. so really the cost is $0
B) You get it because it will prevent you from getting the flu if “they guessed right” which is borderline ignorance and you’re not a dumb person. And even if they don’t precisely nail the strain, it reduces the severity.
C) it’s not just about you. It’s about helping protect those around you who can’t get the vaccine. Whether they are allergic to eggs or have some other condition that prevents it.
D) If you’ve ever had real influenza, you would make sure you never get it again.