I know this is an old thread, but with hurricane season approaching, I thought it would be good to revisit.
A great place to buy a cheap generator is a pawn shop. If you're handy with small engines you can easily tell the condition of one and whether or not it's with the price and the use it's already had.
I bought a Generac 7500 EXL from a pawn shop a couple years ago for $250!! And this was a few days before a storm was forecasted to hit the area when I thought there'd be a run on generators.
The only catch was that it had a dead battery and for some reason the electric starter wad missing. No biggie, it has a pull start and starts on the first or second pull.
My favorite thing about the generator is that it has a NEMA 14-50 plug on it for a 50 amp hookup. All the other similar generators only have a 30 amp twist lock plug.
I had an electrician run a 50 amp input receptacle and an interlock kit. It'll run the entire panel for the inside of the house including the hot water heater.
The only thing is that my house has a primary outside panel with the main that also has breakers for the AC, furnace, and stove. But since my interlock feeds the indoor panel, I can't run those 3 things.
Not to get too off topic, the pawn shop is a great place to buy air tools, corded power tools, and small engine equipment.
I also bought a push mower for $40, which I promptly converted to run on propane. More on that in another thread.
Overall im happy with the generator, except it's LOUD. I'll take some advice from the thread about quieting down generators.