i think if you can get 7-8k miles from high performance tires (like RE11's) that's super.
if i lived in LA and carving the canyons they will probably only last me 3K miles. that's how often i was replacing SP8000's i was running at the time (like 15yrs ago..).
so this is why for someone looking to dd their cars + fun, ContiDW's are a great choice.