The Yamaha EF2000iS is one of the most popular portable inverter generators on the market. Yes inverter generators are more expensive than standard portable generators. And compared to a standard 4000watt generator, you often get half as much power for 2-3 times the cost.
Do the benefits outweigh the cost? Read on. You are the only one who can make that decision. The benefits are that for delivering 2000 watts peak power, this inverter generator is much quieter, lighter and fuel efficient than a similarly powered non-inverter generator.
Inverter generators are the choice for powering sensitive electronic equipment, including computers. They deliver AC power in the form of pure sine waves which are cleaner and more reliable than most generator power sources. For supplying power to emergency medical equipment, I would consider nothing else.