is it a smart investment to buy a "high mileage" car cash?

[omniscententity]

so mechanics, i am wondering if its stupid to buy a car that has 70,000 to 125,000 miles on it. Most dealerships say they run "like new" but really what am i getting myself into when i buy one? the main reason i consider buying a car cash is to pay lower insurance and not have to hassle with a car payment. if something were to go out or break couldnt i just fix it?