I have an office for 3 reasons. 1) They gave me one when we moved (2) my job requires me to have difficult and sensitive conversations with employees and clients and (3) I spend lots of time on conference calls.
In the end though, the best reason not to move is that there is no pay raise. A move should involve an appreciable jump in salary or an opportunity for one in the near future.
You obviously made a good choice for reasons 1, 3, and 6. (Not that I want you to work in a cube.)
After 6 years of consulting, I became accustomed to working in whatever cube, conference room, or broom closet that was available. When I took my current job, it was apparently significant that I was given a "big" office. I still spent the majority of my time in conference rooms.