We are looking to visit Paris for several nights over Thanksgiving this year. We like nicer hotels and are willing pay up to about 500 euros a night per room, but will probably need two rooms for our family with 3 kids (ages 16, 12 and 12). We would prefer a place with a nice breakfast available as one of our children is extremly picky and buffets tend to help by offering options. We want to be either in Le Marais or St. Germaine but certainly negotiable as long as there are lots of non-touristy restaurants and cafes (for the rest of us who are serious foodies). I've looked around and found a couple, but as I've never been to Paris, I could use a little help.
500€ per night per room is a good budget but it will not get you a luxury hotel in Paris. Is there such a thing as a mid-price luxury hotel? In Saint Germain in your price range, I suggest Hotel da Vinci. They have an excellent breakfast. We are a family of four so I am not sure if they have triples. Another option in that area is Hotel Odeon Saint Germain. In Le Marais, I suggest Hotel Les Tournelles. They do not have triples but they have at least one adorable single room.
The Hotel Eiffel Turenne has two rooms one a classic room and the other an Executive Triple room for 2029.00 That was for 3 nights Nov 27 until Nov 30. We have stayed there in the past and enjoyed it. I suggest you go to booking.com and put in 2 adults and 3 children with their age and you will get many choices. The Hotel Eiffel Turenne is in the 7th. and we have been staying in that area since the 90's. You will be blocks away from the Eiffel Tower and many good cafes and restaurants. When you find something that meets your requirements come back here and people will comment.
The Relais St Germain is lovely and has a fantastic restaurant (Le Comptoir de Relais Saint Germain. which doesn't take reservations but the hotel staff helped us with getting a table), the breakfast is for hotel guests only and while not a buffet per se, there's a great selection that is is included in the room rate and all items are from the best purveyors in Paris. The rooms are small so go for the largest you can afford within your budget. Wonderfully situated.