Sorry if my opinion offends, but finding a superb expensive restaurant in Paris is effortless and incredibly mundane.

The real enjoyment is finding that great little bistro with superior cuisine at profit-defying prices. MJLogan's suggestion of Le C'Amelot is a bulls eye. Some others are Chez Grisette (14 r Houdon near Montmartre), Macis et Muscade (110 r Legendre 17th), Les Zygomates (7 r Capri 12th), and Le Bistrot du Peintre (116 av Ledru Rollin 11th).