Man I must have busted 10 drill bits trying to drill out a broken bolt before I finally gave up on it. I think buying one of these machines would probably cost more than a new treadmill though.
You can get a decent set of reverse pitch cobalt drill bits with screw extractors online for $50. I use them at work on occasion on broken bolts without issue.
Taps need this kind of setup because they're making a new screw hole, get stick and brake off, stuck in the hole as hard as possible.