I live in the county that was hit the hardest during the 2009 ice storm. We were without power for more than two weeks. I started out with a 2000 watt generator that my son-in-law had. Ended up buying a 4000 watt Chinese because it was all I could find. Cost me $400. After the storm it sat in a storage building for a couple years then I got it out and started it and changed the oil etc. Made the mistake of letting it sit for a couple more years with gas that had alcohol in it. Ruined the carb and with another problem, also my fault, it had I just junked it. I got my $400 out of it during the fourteen days it ran continuously providing power for our fridge, freezer, TV, etc. for the twelve people staying in my house. Of course there were extension cords running all over the house but so what. Also we had gas heat and city water.
The point I am trying to make is that some of my relatives and co-workers spent as much as $12,000 installing whole house generators that would come on automatically when the power went off. Those units have been sitting there for years without being used. I spent $400. Don't throw away your money buying a super duper diesel/natural gas powered unit that will be used at most a few hours a year. If you are like me you don't have the money to splurge on a never used gen set. The exception to this would be it there was someone in your home that had a medical problem that necessitated power.
Also make sure you run it until empty of fuel before storing and if possible buy gas that does not have alcohol in it. For sure don't store it with gasohol in it.
With your budget I would get one of the Chinese gensets, make sure you use alcohol free gas, and spent the money saved on something else.
Oh yes, one other thing, my wife could not start the generator. Make sure yours can or be prepared to spent extra for electric start.
RSKY