The cost of a portable generator is often directly tied to the amount of power it will provide. The higher the wattage, the higher the price. This is one reason why it is important to understand that you probably won’t be able to afford to run every single device in your home, unless you upgrade to what’s called a whole house generator. When you’re shopping for the best portable generator, you’re going to be focusing on running just the bare essentials through a power outage.