AZ was negotiated at something like less than 2 euros per shot for EU markets, and the Pfizer contracts varied wildly for different countries but it was negotiated at about 15 euros per shot for EU.
With my cynical hat on if you are having to vaccinate millions that order of magnitude difference probably matters.
What I haven't seen anyone discuss at the EC level is what would be the maths of just paying premium Israel prices for the Pfizer vaccine?
Would the economic benefits of get out of this mess as quickly as possible outweigh the extra euros per shot spent on vaccination. My guess is it would likely pay off but then again I am not a European Commissioner.