Factory Authorized Outlet via eBay offers the DuroMax 3,500-watt Hybrid Dual Fuel Propane/Gas Portable Generator, model no. XP4400EH, for $389.99 with free shipping. That's $10 under our mention from last spring and the lowest total price we've seen. (It's a current low by $110.) 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.