As it is, we have NO IDEA what it costs to create a vaccine.
If the companies were required to post the actual cost per anticipated dosage, then it would be easy to determine a fair price based on the actual cost, including research.
I see hundreds of ads for prescription drugs every week. These are NOT a production cost. They are usually run because there is a far cheaper drug that they wish to compete with that may be even superior.
According to these ads, these advertised drugs have many undesirable side effects, which include death.