I have the new Harbor Freight 3500 watt inverter generator $649 (on sale)much improved quality with push button start. They have a smaller version 2000 watt inverter generator $499 I believe. They compare quite well to the Honda 3000 ($1995) and 2000 ($999). Reviews on Youtube. No problem running 15000 BTU AC with 3500 inverter generator.
This is the one I installed because it also has a pass through for 120 when camper hooked up to the pedastol. That way if i don’t shut off the inverter it will not cause problems and blow the circuit. https://www.amazon.com/gp/product/B00TI1D5JK/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1