Hey Roy, You ask Any thoughts ?
SURE DO Ive bought and used several true actual Pure Sine Wave Inverters, Alternators and Gensets over many years on Flea Bay, Amazon, Camping World etc etc NEVER SEEN NOR HEARD ANY ACTUAL PSW ANYWHERE NEAR THAT PRICE FOR THAT SIZE
There's lots of hype and downright false advertising going on in those circles. There are much cheaper Modified Sine Wave MSW advertised as Pure Sine and there's lots of surge or short term power ratings advertised out there versus the actual continuous power.
NOTE When a motor starts it may draw 3 to 6 times the current required to run it, and an Inverter or Generator EVEN IF adequately rated only enough for the run load MAY NOT BE ABLE TO START THE MOTOR.
NOTE an engines HP may be rated for such at full RPM so if running at lower RPM ITS NOT PRODUCING THAT HP
NOTE for many typical RV, Marine and Inverter powered loads, DEEP CYCLE batteries are preferred over engine STARTING batteries.
NOTE Each device, Genset, Alternator, Inverter, Engine, Battery in such a configuration HAS HEAT LOSS none are 100% efficient WELL DUH so an Inverter or Genset needs adequate rating and enough capacity WITH LOSSES to be able ESPECIALLY to START a load plus keep it running continuous
Im NOT saying what you propose cant work, IM ONLY SAYING you need adequate rated components and that price sounds too good to be true if it were an actual PSW 6000 Watt Inverter (Yeah Right)
If you figure the combined price of Batteries,,,,,,,Inverter,,,,,,,,Alternator,,,,,,,Engine to turn the alternator,,,,,,,,,PLUS all the complexity, wiring, INefficiencies,,,,,,,and build,,,, MAYBE A BIG ENOUGH GENSET MAY BE THE BETTER ROUTE Im ONLY saying, its your choice, what you propose WILL WORK if allllllll the components are adequate rated
John T Live in the RV in Dunellon Florida