No Shopping Required
There is a particular staleness to a room that has not moved in a year. It is not dirt and it is not clutter. It is that every object has been in the same position long enough that you have stopped seeing any of it.
The fix is subtraction, rotation and light, in that order. Clear one surface completely. Turn a single chair fifteen degrees toward the window. Move one lamp from the corner into the middle of the room.
Twenty minutes later the room reads as new, and nothing was bought at all. Do it before you decide you need something.