There is a simple answer:
FOLLOW THE MONEY!
FRom https://www.yahoo.com/now/much-covid-19-vaccines-cost-121559953.html
Here’s a breakdown of how much each drug company has received to date, not counting money the federal government used to purchase the vaccines. So far, the government has placed substantial orders with both Pfizer, whose vaccine goes for approximately $20 a dose, and Moderna, which sells its vaccine for up to $37 per dose, CNBC reported.
Pfizer and BioNTech received $1.95 billion for delivering 100 million doses to the U.S. These firms did not receive any funding for research & development.
Novavax
The U.S. Department of Health and Human Services and the Department of Defense signed an agreement to pay Novavax $1.6 billion to produce 300 million vaccine doses. The vaccine has not yet been approved.
AstraZeneca and Oxford University
The Biomedical Advanced Research and Development Authority, part of the HHS office of the Assistant Secretary for Preparedness and Response, awarded a $1.2 billion grant to the biopharmaceutical firm and the university, which are working in partnership to develop 300 million doses of their vaccine.
Janssen Research & Development
This Johnson & Johnson subsidiary got $456 million in R&D funding from the government and $1 billion during the summer to produce 100 million doses.
Moderna received $955 million in the form of three federal grants. This money does not include purchases of the vaccine and was used on R&D and testing.
Merck and IAVI USA
These companies received $38 million in federal funding to develop a single-dose vaccine that will be delivered orally.
As the government continues to fund vaccinations across the U.S. through 2021, no doubt these costs will increase.
And then, there is this (see chart at): https://www.statista.com/chart/23658/reported-cost-per-dose-of-covid-19-vaccines/