Saints to sign LB Kiko Alonso

I wonder what the cost difference is between the respective deals of Kwon and Alonso. On the surface, it surely seems like the former would have been preferable.
So they wait until Kwon is signed by the Jets, then go get Alonso, who hasn't played in forever because of injury? I mean I guess they have their reasons and all but from where I sit Kwon would have been the better choice.