There is a risk of fire and loss of fuel in the event of a lightning strike or other accident or theft, so the person has to consider that before jumping into the idea. The fuel tanks should each be grounded, and they should be situated away from the house and trees to minimize damage should they catch fire.
If the motorist travels take him far away from home, the cheap gas sitting back home does him no good. He can only save on gas when his travels are local such that he would fill up at home.
There may be restrictions on having bulk fuel stored within city limits too since it poses risk and health hazard to the neighborhood, particularly, fumes.
People should also consider that having hundreds of gallons of fuel in storage is going to help them in the event of a shortage of fuel due to loss of electric power, oil embargo, terrorist attack or natural disaster. They might be able to run their generators longer than others, and perhaps use it for barter, but that’s about it.
When electricity stops, the fuel pumps stop. When fuel runs out or the pumps stop, the trucks stop running, and when trucks stop running, everything comes to a standstill.