all 3 of these 3000 watt inverter/chargers appear to be the same but there is a large price point difference ? I'm totally new to this im rebuilding a13 foot 1967 travel trailer and needed to do mostly off grid camping mostly 2 or 3 day stays generator inverter use. when im selling at art fairs out of town. 2 and 3 day hotel stays are realy starting to hurt the bottom line
