At that price one could hand out first class air tickets and limos to and from the airport to those who would use the train for the rest of their lives.
Really. Think about it. Set up high speed turnoffs and a separate terminal just for an autonomously piloted shuttle Airbus. Sort of like 500mph touch-n-go’s from Seattle to San Diego. Allocated airway and STAR & SID to provide automated landings and takeoff.