In response to other Regalade type restaurants, I would highly recommend Chez Michel in the 10th. The chef, Thierry Breton, also trained under Christian Constant and the food is excellent. The menu is 30 € for 3 courses. The neighborhood is not the greatest though, so you may want to take a cab. Also, in the 15th is Le Troquet. Another great place with remarkable food for the price. The menu is 28 € for courses and 30 for 5, but there is no choice! I recently had a delcious meal at Alain Ducasses latest restaurant, Aux Lyonnaise, and loved it!