There is a mis-conception that impact glass will not break during a storm. That is not entirely true. Impact glass is very resistant to wind loads and should not break due to wind load during a storm but may break when hit by wind borne debris. Should the impact glass break, you now have to replace the impact glass therefore adding a long term cost.
Which brings us to the point about convenience. With Impact systems you do not have to run around and hang/close shutters every time there is a storm warning.
It's cost or convenience, barring locations that don't allow shutters or where impact systems are not required, if you choose cost, go with a non-impact system and shutters, if you favor convenience, go with the impact glass.