As far as I know, ULA's track record for reliability is much better. Last I read, maybe a few months ago, SpaceX launches had failed 1 in ~19 times, and ULA's failed zero in ~85. I wonder how the Air Force addressed this issue. Perhaps the cost of failure is less than the premium for reliability; perhaps they evaluated reliability based on something other than the track records (e.g., an engineering review); and of c…
But these GPS satellites are only in the $100m dollar range according to the internet so it just doesn't make sense to pay an extra $50m to go from 97% reliability to 99.7%.