Headlight bulbs? Anywhere from 50-100 which include parking lights. I've tried led Parkers and they weren't great as the beam is to focused so it didn't bounce off the reflectors.
If you're talking entire headlights probably around 4-500 depending where you shop.
Good choice with led interior too. I Love my LEDs - I haven't done the vanity mirrors yet and probably won't. Can't be bothered.