How much does it cost to change a clutch cable?

I have a Nissan Micra S, 2002. Recently the plastic bit on the end of the clutch cable broke, and I took it to the garage to be repaired. They have replaced the whole clutch cable, and charged me a total of £90 - £37 for the cable, and £40 for an hour of their time, plus VAT.

Now, this may be entirely reasonable, but I just don't know! I was hoping someone could tell me how much a clutch cable generally costs, and how long it would take someone who knows what they are doing to fix it. It would also be nice to know whether it was really necessary to replace the whole cable, or whether it is possible to just replace the plastic bit on the end which was snapped. I did ask about this, and the mechanic said that he had to replace the whole cable because the plastic bit was crimped on.

I would appreciate any replies to set my mind at rest.

Thanks