Factory Authorized Outlet via eBay offers the DuroMax 3,500-watt Hybrid Dual Fuel Propane/Gas Portable Generator, model no. XP4400EH, for $399.99 with free shipping. That's $100 under our December mention, which included a $15 credit, and the lowest total price we could find by $249. It features a 4-gallon fuel tank, power panel with engine shut-off switch, volt meter, and eight hours of run time at 50% load capacity.