I'm thinking it could be tough to make that budget for a week in Paris. Have you thought about an apartment? Chezvous.com is a web site that lists properties and although I have not personally used it we do know people who have with good results. Also, if you go in warm weather don't miss a walk on the Ile St. Louis making sure to stop at the Bertillion shop for ice cream (lots of restaurants have the Bertillion sign indicating they sell it but go to the original for best selection of flavors). And I would recommend a visit to the Saint-Chapelle - preferably on a bright sunny day when the light coming through those wonderful stained glass windows just dazzles. If you're going to museums get the museum card if for no other reason than that it allows you to avoid the entry lines!