Before making a decision check how much fuel the larger units use. They use almost as much just running as they do under load unless you get one of the inverter ones.
If I had any other use for Diesel fuel I would look into the Diesel powered generators if wanting a larger one.
As my power seldom goes out I have had a gasoline 5 kw for a number of years, but a few years ago I bought a 4 kw dual fuel to run on propane. That way if the power is out for only a few hours I use the propane and do not have to worry about draining the fuel out or it going bad in the generator. At the time I bought the dual fuel it was only about $
350 shipped to my house and that included a battery to start it with.