It should be noted that 'self sustaining' only means that the entire pellet undergoes fusion. The process still stops after a few instants of time, requiring a new pellet of fuel, a new laser burst (consuming at least twenty times the power that gets deposited in the plasma), and worst of all, a new monumentally expensive hohlraum, machined to nanometer precision.
Yes, should have said energy. As for hundreds vs twenty, my understanding was that newer lasers than what NIF is using should be in the twenty times range, but you're right that at NIF they use hundreds of times more energy than they can deliver to the plasma.
