It was a great move by the Falcons. Bush can start in the league and be a good safety. For the Saints he provided valuable depth. The Saints employ 3 Safeties often. For Bush, I think it is an excellent opportunity. For the Saints, they will use that cap space elsewhere but will not be able to find someone as good.
I am doubtful that the Saints match the offer.
The funny part is that Bush started his career with the Falcons as an undrafted free agent.