eVTOLs are going to be much more expensive to build than helicopters because they have far more stringent weight/strength requirements due to low battery energy density (relative to aviation fuel).
The idea is to have far cheaper operating costs. Electric motors are far more efficient than ICE, so you should have much cheaper energy costs. Electric motors are also simpler than ICE so you should have cheaper maintenance with less required downtime compared to helicopters.
Of course, most of this is still being tested and worked on. But we are getting closer to having these get certified (FAA just released the SFAR for eVTOL, the first one since the 1940s).
The idea is to have far cheaper operating costs. Electric motors are far more efficient than ICE, so you should have much cheaper energy costs. Electric motors are also simpler than ICE so you should have cheaper maintenance with less required downtime compared to helicopters.
Of course, most of this is still being tested and worked on. But we are getting closer to having these get certified (FAA just released the SFAR for eVTOL, the first one since the 1940s).