Why not buy the S-400/500 or even THAAD?Not bad ,they have good background .
But I've some notes:
In Iran case, we don't need the toys such anti-missile defense systems or defensive platforms .This is no more waste of money ,time and effort.To face the threat of the missiles we have to start our own missiles program. To stop their missile you've to be already have a missiles in order to achieve the deterrence .Otherwise, we will be like a goalkeeper ! they launch their missiles and our job is to repel the missiles and I wonder how long we will stand.
- Sejil missile is active in service and they're 3 variants Sejil-1,Sejil-2 and Sejil-3 .(Sejil-3 under development )
- Safir missile also operational .The Iranians claims that they launched a satellite using it .