The Indy and Mariner have some 5 night sailings within that budget ($1,200 for two people) in an interior if you're happy with a 4 night - the Allure also has some that fit the bill.
The Indy also has the same price for balcony on 4 night itineraries. I'm sure you can do a search with your preferred dates and find some good options that are on newer/bigger ships than Grandeur.