Except you also have the turbo-prop to be taken care of.
OK, lets assume that this is a production model and the big prop is gone.
Yes, annual cost per motor should be much less than for ICE - but you do have a bunch of them. And, of course, the turbo-generator will have its own annual cost.
Another cost cutting feature: fixed bladed props.
I wonder what the TBO or TBR is for the electrics?