By paying for business interruption policy you will receive compensates for your lost income in case you have to vacate the premises of your company due disaster that is covered by your insurance, such as fire. This insurance covers the revenue your company would earn in case of disaster did not happened. Also, the policy covers operating expenses such as electricity, that continues even though your company is temporarily closed.
How much the policy will cost depends on how big is the risk of a fire or other disaster that may happen and damage your premises. For example, the price would probably be higher for a restaurant than for a real estate agency, because of the higher risk of fire. Also, for a real estate agency would not be an issue to move and operate from another location for a given period of time.
Depending on how big is the disaster, it can take more time and people until your business gets back on track. Because of this, make sure the limits of the insurance are sufficient to cover more than several days. Generally, there is a waiting period of 48-hours before business interruption coverage kicks in.
Paying some of the extra expenses means that the insurance would reimburse your business for a reasonable sum of money, so you do not have to shut down during the period of restoration. This expenses will be paid if they can help to decrease the costs for business interruption. Some companies offer the opportunity to pay for extra expense insurance alone without purchasing business interruption insurance completely.