How Much Medical Evacuation Insurance is enough?

There are several Med Evac plans that offer $100,000 coverage and a couple that offer $500,000 or even unlimited. Any suggestions on how much is enough coverage for a MedEvac from Europe?

For Western Europe, $100k should be more than sufficient if the plan covers evac to "the nearest suitable medical facility" simply because your "evacuation" is likely to consist of an ambulance ride from the nearest port. If the plan covers evac to "the hospital of your choice", I'd get a higher limit.