It is well known that AZ sells the vaccine at cost. E.g. "... is being offered by the drugmaker at cost during the pandemic and at no profit in perpetuity for low-income countries." [1] That's because the vaccine was developed by the Oxford university and Oxford made this a condition. If AZ makes a profit from the vaccine during the pandemic they would break the contract with Oxford.

It seems the cost price differs from country to country because of different production costs and other factors (maybe shipping).

[1] https://www.politico.eu/article/astrazeneca-vaccine-cost-hig...