I think a firearm is worth more than a flu shot.
I learned that there are 10,000 strains of the flu and CDC does a statistical analysis to identify the top three prevalent strains for the year. In short, they can be off by 9,997 strains. Opps. So there's no guarantee that the immunization received will protect the person during that particular year.
Besides, a $20 flu shot doesn't compensate even for a $300 gun.
Vigilantibus et non dormientibus jura subveniunt. Molon Labe!