I am not a fan of inside cabins either, but I had one on the Rock Legends cruise in January on Liberty Of The Seas. As Sonny said, price trumps location sometimes. Now, that was a full-ship charter with high fares to pay for the bands, but regardless, the cheapest cabins on the ship were insides at around $2000 for 4-nights. A balcony was almost double that amount.
Of course, being on a lower deck can be a problem in extreme situations, such as the recent Carnival Triumph event. The dividing line between 'it was a nightmare' and 'it was rough but we managed' seems to be where the decks with balcony cabins started.