The current prescription charge is £9.15 per item. That’s quite a lot for some. But there are exemptions of course. They probably still represent a relatively small proportions of the total drug cost in many cases.
Big pharma can be viewed as a necessary evil. Of course they profiteer. But there are two sides to big pharma, the corporate side which has to make big money by any means, and the scientific side which in many cases is essential to modern medicine. These giant corporations also have large overheads and the developmental cost of drugs can be very high and sometimes an investment in a certain drug can lead to large losses when the drugs are not found to be effective or have side effects. But of course we need them especially when they will be able to scale up the vaccine we are all waiting for, for SARS cov2, which I am sure you will be first in the queue for.