thanks. ScoopLV, I'd be in both camps eating and art. We decided to spend the night in Paris and then train to Blois, spending a few nights, where we're going to take the special shuttle bus Châteaux Rémi 2 days to see 4 chateaux and eat at a great little restaurant in Blois (2X) on this trip.
Here are a few of my favorite "bang for the Euro" restaurants in Paris, and one in Epernay. All of these restaurants are "cheap and cheerful."
Paris:
#1 - Bouillon-Chartier. 9th. One of my favorite restaurants, period. This is old-school Paris. It's been popular since forever. And they ONLY do the classic dishes, unironically. The menu hasn't changed since the 19th century. The waiter will write your order on the tablecloth. Your dishes arrive. The wine is inexpensive and decent. And it's a mix of tourists who have dreamed of eating at Bouillon-Chartier, and French tourists in Paris who have also dreamed of eating at Bouillon-Chartier, and Parisians. Inexpensive, unfussy food in an absolutely beautiful dining room. If you ate here every single night, I wouldn't blame you.
#2 - Domaine de Lintillac. 7th. The best lunch special in Paris, period. Some of the best duck dishes on Earth. They serve duck. They don't serve much that isn't duck. Go here. Eat duck. Only Beijing can claim to do duck as well as this restaurant. It will cost less than 20 Euros for lunch with wine. If you eat lunch here every day, I wouldn't blame you.
#3 - Au Pied de Cochon. 1st - in the old Les Halles. They serve pigs feet with bernaise. And that's what you want to order. Fabulously good. They serve a great deal of seafood as well. But if you're here for the first time, get the feet and enjoy. After lunch (I recommend this for lunch), wander around the culinary supply stores which still hang on -- E. Dehillerin at the top of this list.
#4 - The entirety of Rue Cler. Just wander and nibble. This is one of the world's great streets. Lastre Sans Apostrophe, around the corner on Rue Grenelle makes some of the best pate I've ever had. Just wander around this area and window-lick.
#5 - Epernay -- La Chapon Fin. Much like Bouillon-Chartier, unironic classic dishes. (Not nearly as pretty a dining room. But who cares? Walking distance from the train station in my favorite Champagne town.) This place is so good, that after lunch we immediately made dinner reservations so we could try two new entrees.
There you go. All of these places aren't that much more expensive than US fast food.