OP is implying government or its contractors is the one grifting, not Assange . Basically forcing a large bill on a person who has no choice but to accept .
It is not grift though, it does cost in that ball park for international private long distance flights in the 10,000+ mile range . Planes that can do this like say gulfstream V would seat 15-20 people , so like 25k per seat , it is not that much more expensive than a first class ticket cost wise if you think about it