When you die in a mission, you’ll have the option to restart from the last checkpoint or restart the mission without other consequences. However, if you die while free-roaming, you’ll respawn from a nearby location where you died, and lose a certain percentage of your current money. The amount deducted to your money will increase over time if you end up dying a lot of times within a short span of time. Since the deduction is based on the amount of money you’re holding, dying can be seriously expensive.