If you were not welcomed aboard on your first postings, then let me be the on to do so. Welcome to Cruise Chat!
You question has been discussed before I assure you. It really depends on how you booked (through a travel agent or on your own) If you booked through a travel agent, a good one will watch the price for you and if they see a drop, they will request a credit (many times this will just be a reduction in your final payment amount or it could come in form of on board credit) Note that they may not reduce your price in each case but most of the time they will. It also can depend on the cruise line policies. Carnival is pretty good about making apples to apples price changes good even though they don't have to do it. If you booked on your own you can check on the price periodically and if you see a drop, call your PVP at Carnival and request an adjustment.
In the end its one of those things that fall under the "it doesn't hurt to ask" category.
As far as if your cabin is a good location, that can be subjective and a personal choice. 2281 is close to the elevators, this can be good if you are not one that wants to walk a long distance to the elevators and it can be great coming back from excursions as you can get back to your cabin (the normal first stop from port) quickly. The drawback can be noise from people coming and going from the elevators. The way the elevator lobby is designed minimizes this noise but it can still be there. It may not even bother you if you are out late and come back after the main shows when the crowds have gone...
Carnival Cruise Lines:
Fantasy 90, Celebration 95, Victory 05, Conquest 05, Spirit 6/06, Freedom 6/08, Holiday 7/08, Victory 6/09, Valor 9/09, Dream 6/10, Splendor 8/10,Conquest 8/11,Magic 11/11,Triumph 4/12,Spirit 7/12,Freedom 11/12, Triumph 2/13 - The fire cruise
NCL Dream October 2006, RCCL Mariner OTS June 2007