Yes, that would reduce the wattage needed to start, however, in my opinion it's just not worth it. The unit only pulls 250 watts for the first five minutes or so (igniter = 200, auger and fan motors = 25 each) then it drops to 50 watts max when both motors are on.
You can pick up a very nice 400 watt inverter for around $30.00 at Sam's Club, Costco or such. I've used them on audio amplifiers and if there is any noise or irregular sine wave, it will show up there.