I guess you don't read NY Magazine http://nymag.com/nymetro/food/features/11044/ (albeit from 2005)

Otherwise, it is trivial to spend >USD 500 at any reasonably good restaurant in the world, just order a few ounces of beluga caviar (that covers about 4 oz. at retail, so not a huge amount!). There are thousands of restaurants world-wide that will special order it for you, though few keep it in stock.

As for prix fixe menus, their price point really varies by market more than by restaurant quality. Also some chefs prefer to keep their best dishes a al carte. Sadly it is hard to find good meals in much of Europe for under USD 200 per person these days, at least in this type of restaurant. Of course some of the best food is found elsewhere, often dirt cheap (as in under USD 10). But your question had nothing to do with food quality.