Main breaker of fuse box won't turn back on?

In replacing an outlet, my father turned off the main breaker of our fuse box (which is pretty old). The issue is that now, it won't turn back on. My father called an electrician who told him that the main breaker won't be able to turn back on due to its age and the fuse box has to be replaced at a pretty hefty (~$2-3000) cost. Is there any way to fix this without having to get the electrician involved? Or, if an electrician must be involved, is this an appropriate cost?

Edit: Just disconnected the new outlet and the main breaker still won't turn on. :(