From the Torygraph:
However the redacted contract, which does not reveal how much was paid, states that "AstraZeneca has committed to use its Best Reasonable Efforts... to build capacity to manufacture 300 million Doses of the Vaccine, at no profit and no loss to AstraZeneca, at the total cost currently estimated to be [redacted] Euros for distribution within the EU, with an option for the Commission, acting on behalf of the Participating Member States, to order an additional 100 million Doses."
This morning the Spectator reports that when ministers saw a similar offer in the UK contract, Alok Sharma and Matt Hancock "insisted on a legally binding promise to serve Britain first", which they later received.