If you're planning on being a teacher and not a professional performer, there's no reason why a good BBb horn won't do the job for you. Save your cash.
Your moving office photo seems to be inspired by Harry Potter.
Unless you are planning to audition for a major symphony orchestra there is no reason for you to switch to CC tuba. You will save a lot of money and avoid a lot of frustration if you stay with BBb. Have fun!