(snip) I would guess that the $500 model from eBay is MSW instead. (snip)
I have read that with the modified inverters they can handle small loads pretty well but a pure sine wave inverter needs to be nearly maxed and smaller loads will burn them up quicker.
... Psw are generally slightly less efficient than msw under similar power usage levels...
I have been looking at some inverters. My ? is do all of them have 3 prong plugs for the 110 side or do they have some for direct wire with electrical lugs like what is on the 12v side.