I had taken the single Adult tour which cost me GB...

I had taken the single Adult tour which cost me GBP 27.5. They have guided tours included as part of this ticket and they help you with the history and understanding the structure how the castle evolved over years. Nothing but a typically guided tour at a heritage site. The guides are called the Yeoman Warders who are also popularly known as beefeaters.
However, this guided tour doesn't include you tour to the Crown jewels, which is the most worthy attraction of this site, and there is a separate queue for this. To view the Crown Jewels, it usually takes an hour keeping in mind the queue. Another major attraction here is the White Tower, where all the British Armoury is in display.
I would suggest not to take the guided tour if you are not very much interested in the history of the tower. There are recorded guides which you can pick and they will help you save time as well.