I’m also a ‘76 owner. Welcome. I’ve never paid a locksmith to make a new key, but $250 seems high. Especially given that we’re talking about an old analog key that won’t require a chip or any sort of programming. In any event, even at $250 it would probably be cheaper (and far easier) than replacing the ignition lock at the end of the day. IIRC repo ignition locks aren’t cheap. And you have to take apart the steering column, which is a huge pain.