Ebay offers Refurbished  Firman 7500W/9400W Tri-Fuel Generator for $649.99 (reg $1000) with free shipping.

Product Description:
The REFURBISHED FIRMAN T07571 tri fuel generator is a 9400 watt trifecta with the ability to run off of gasoline, propane, and natural gas and comes with an electric starting system. Including a 5.5ft LPG hose for convenience using larger tanks, the T07571 is also California emissions certified. Its 8 gallon tank runs for 12hrs and at 74dB. Our Max Pro Series 439cc engine runs cool and efficient thanks to its Phoenix Fat Head Block. With a built-in 10” wheel kit and folding handle, the tri fuel T07571 can go anywhere and perform however you like.