Try La Truffière in the 5th arrondissement, at 4, rue Blainville very close to the sympathetic Place de la Contrescarpe. Very good food and intimate athmosphere, and you should be able to make it for FFR 1,000.

A couple of other nice ones, but on the wrong side and a bit more 'populaire' are La Bastoche at 7, rue St-Antoine and the more brasserie-type Le Grand Colbert at 4, rue Vivienne, next to Jardin du Palais Royal. You get very good food at decent price in both these places but La Truffiere is really my favorite (used to live right next door for my year of studies in la ville de lumière). Bonne chance for getting a table and Bon appetit!